Difference between revisions of "G2p Analysis Minutes"

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	Minutes of the weekly analysis meetings		Minutes of the weekly analysis meetings
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		+	[https://hallaweb.jlab.org/wiki/index.php/G2p_Weekly_Analysis Agenda]
−	<B>11/16/2011</B>:
−	Present: Jixie, Melissa, Min, Kalyan, Alex, Ryan, Jie, JP, Karl
−	Pengjia, Chao and Toby went to NIST helping target irradiation.	+	==07/29/2021==
		+	Present: JP, David
−	*JP:	+	*David showed a zoomed in plot of the Q^6 Delta_LT scaling agreed upon last week, and JP and David both agreed that this made the high point look unnecessarily bad. David agreed to make a similar version of the Q^4 plot to decide between next week, and include the Q^6 plot in the current paper draft.
−	1) In the coming commissioning, 1,3 or 5 passes beam will be available for Hall A.<br>	+	*David mentioned that he found Chao's internal presentation of an elastic study which yielded a contribution to the acceptance systematic of 4%. JP commented this was likely to be the dominating systematic for the acceptance and suggested that David use this to obtain a back of the napkin calculation of the XS systematic. JP also suggested that this systematic could be representative of our overall uncertainty in the 1.15 scaling to match the g2p data to the Bosted model, and that we could potentially quote this number to anyone who raises issue with the scaling factor.
−	The beam energy is about 580 MeV per pass, we prefer to 3 pass beam. <br>	+	*There was a brief discussion of the Drechsel paper JP found, he suggested Karl would probably have access and that the discussion in that paper would likely feed what we should say about d2 in our paper.
−	2) Need to write the TOSP for the commissioning.	+	*David mentioned that he has been working this week on making a draft of the paper with Karl's comments from last week and JP's comments from this week, and would try to finish in the next day or two to send to the Spokespeople.
		+	*David will be traveling next week but available for a meeting, JP suggested if the draft was sent out this week it would be a good time for a short meeting for Karl, JP, and any others to share their current thoughts and comments on that iteration of the draft.
−	*Kalyan:	+	==07/22/2021==
−	1) Working on the HV crate.	+	Present: Alexandre, JP, Karl, David
−	2) Bogdan suggested to replace all the TDC to 1877s. Need to evaluate how much work and how much risk <br>	+
−	it is to implement this upgrade.	+
−	*Jixie, Min :	+	*David showed a number of slides showing delta_LT multiplied by various powers of Q2.  We commented that Drecschel shows Q6/M2 delta_LT in his paper. Also the 2004 E94010 polarizabilities showed the same quantitty. So there is precedent for this. David will produce a zoomed version of the plot.  He also showed delta_LT/gamma_0, although he has low confidence in the present error bars. He will revisit and he and Karl will try to add RSS data, Maid and pdfs to see if the transition to the predicted scaling at very large Q2 is at all visible at this very low Q2.
−	1) HRSMC v0.99 released.  In this version, HallB magnet geometry and field is built in. Full size <br>	+	*JP Asked David to look at threshold again, and to try to dig out Chao's evaluation of the acceptance uncertainty from the elog and old wiki presentations.
−	scattering chamber is built. The local dump stand is also in position. <br>	+	*Alexandre reminded that there is a lot of good old information in the elog : https://hallaweb.jlab.org/dvcslog/g2p/
−	2) Talked to Jack about measuring the septa field.  Jack still working on the power supply, might be <br>	+	*We switched the weekly meeting time to 10:30am on Thursdays.
−	ready next week. Jixie need to get the TOSP ready as soon as possible. <br>	+	*Karl will be on travel next week, but expects to be available for the weekly meeting.
−	3) Finished checking the tosca map with the fortran routine for the HallB target magnet. They match each<br>	+
−	other very well. <br>	+
−	4) Studied the homogeneity of the hallb magnet. See the figure [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20111116_HallBCoil/Homo_HallBTgField_RZ.png here].<br>	+
−	Compare this coil to the SANE coil, see plot [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20111116_HallBCoil/Tg_SANEVsB.png here]. <br>	+
−	5) HallB field data map for snake is ready. Download it [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20111116_HallBCoil/snake_targetfield.map here]. <br>	+
−	6) Working on a new model for sieve to target reconstruction.  The one from MUDIFI is not good at all. <br>	+
−	Trying to improve it with new fits. <br>	+
−	7) We would also like to have optics runs in the commissioning. Those runs will be used to improve the <br> reconstruction based on MC data. Need to know the target position before hand.	+
−	*Alex:
−	1) Commissioning todo list (run plan) is already in the Elog, see entry [https://hallaweb.jlab.org/dvcslog/g2p/143 143] and [https://hallaweb.jlab.org/dvcslog/g2p/144 144] for details. <br>
−	*Jie:
−	1) Learning to run the G4 program.
−	*Ryan, Melissa:
−	1) EDTM for left arm is working now. <br>
−	2) Run left HRS in buffer mode. Found 40% dead time. Will investigate this issue in the rest of this week.<br>
		+	==05/01/2019==
		+	Present: JP, Karl, David
		+	'''Feature Presentations :
−	----	+	*David
		+	Showed a number of slides building up the 2.5T 2.2GeV dilution one step at a time to try and analyze any outstanding issues. These plots showed severe edge effects from the momentum settings on all run types. J.P. and Karl suggested fixing this by doing a fit to one of the yield, and then using an offending momentum setting to find a dp correction to the fit and apply it everywhere. The plots also showed several momentum settings where the centroid appeared to be shifted, David promised to do some detective work to try and figure out why.
−	<B>11/09/2011</B>:
−	Present: Jixie, Melissa, Min, Kalyan, Alex, Vince, Ryan, Jie
−	Pengjia, Chao and Toby went to NIST helping target irradiation.	+	'''Verbal Updates:
−	Alex  is still working on the commissioning plan.	+
−		+
−	*Kalyan:	+
−	1) Prepare to move 3rd arm DAQ behind the green wall <br>	+
−	2) Setting up the helicity scaler gates <br>	+
−	3) Decided to use the beam line HV crate <br>	+
−	4) Making magnetic shielding for PMTs <br>	+
−	5) Trying to improve the reconstruction matrix from sieve to target <br>	+
−	*Jixie, Min:	+	None
−	1) Posted the optics discussion and TODO list in [Elog https://hallaweb.jlab.org/dvcslog/g2p/136] <br>	+
−	2) Put HallB coil geometry into the G4 model, field module also ready to use. <br>	+
−	3) Working on compare the TOSCA model with the routine from Peter Bosted <br>	+
−	4) Running simulation for GEP to determine the magnetic angle, (Urgent! need to finish by Thursday) <br>	+
−	5) The bremsstrahlung result can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20111108_Brem here] <br>	+
−	*Jie:	+	==12/06/2018==
−	1) Learning to run the Geant4 program	+	Present: Karl, Chao, David
		+	'''Feature Presentations :
		+	None.
		+	'''Verbal Updates:
−	*Vince, Ryan,Melissa:	+	*David
−	1) Jack finish install the 3rd fast-bus crate for left arm. Ryan updated the crate map and <br>	+	Discussed a final issue with Chao leading to simulated peaks being smeared too wide, because of a smearing parameter in the input file being too big. Said he should have final 5T Longitudinal packing fractions next week, and is prepared to have final 2.5T 2.2GeV packing fractions once Snake Model is complete. Also showed a plot of Gamma 2 indicating that the cost to using just the Material 8 data for the 2.2GeV 2.5T would be costly, more than doubling the total error bar and changing the central value slightly, highlighting the need to use one of the other methods discussed to complete the analysis.
−	took cosmic run to check left HRS DAQ <br>	+
−	2) Melissa continue her work on identify the source of low efficiency of right shower. She found that	+
−	there is 1~2 blocks of shower give low signal. She will spend more time to look into this.	+
−	3) Vince, Alex, Ryan will meet with Bob in Thursday to plan a DAQ rate test.  This test is trying to <br>	+
−	learn how much will be the improvement after install the 3rd fast-bus crate. They might test it again once<br>	+
−	Pengjia finished installing the HAPPEX crate into the left HRS.	+
		+	*Chao
		+	Chao said that he will be needing to leave the field and seek a job in industry starting in January, but said he would finish updating the Snake model before he goes so that the packing fraction analysis can be completed with the new method.
−	----	+	==10/04/2018==
		+	Present: J.P., Karl, Chao, David
		+	'''Feature Presentations :
−	<B>11/02/2011</B>:	+	*David
−	Present: Jixie, Melissa, Min, Chao, Pengjia, Kalyan, Alex, Vince, Toby, JP, Aidan, Ryan, Jie, Yawei Zhang	+	Showed several slides on the current status of the 2.5T packing fraction. With several issues fixed, the carbon peak shows good agreement with the helium peak subtracted by using a helium simulated elastic peak and subtracting it scaled by the appropriate packing fraction. For the production data, this process was repeated with an iterative process for the packing fraction of helium, showing no sensitivity to initial guess and converging on relatively reasonable packing fraction results. J.P. and Karl suggested that the fit between the simulation and the data is not perfect, it may be a reasonable enough comparison to function. However, for Material 7, the elastic yield is much sharper than for Material 8, and while the latter matches the shape of the simulation well, the former looks very different. Karl suggested to look into how the materials compare to the simulation for other settings, and J.P. noted that it should be impossible to compare the integrated yield to the simulation if their shape is different. It was also suggested to check on the status of the septa, and see if the simulation has accounted for any possible changes in it.
−	*Alex:	+	==09/27/2018==
−	1) Got permission to use Hall-B magnet, will be ready around mid Feb. <br>	+	Present: J.P., Karl, David
−	2) Will have commissioning from 12/9 to 12/24  <br>	+	'''Feature Presentations :
−	3) will work out the commissioning plan then determine the shift schedule <br>	+
−	4) Need to finalize the GEP angle. 7 +/- 2 degrees are all acceptable. <br>	+
−	Jixie will put the geometry into the G4 model and help to finalize that<br>	+
−	*Kalyan, Chao:	+	*David
−	1) Find out a way to disable any channel of the ADC for the 3rd arm DAQ. After disable some unused channels,<br>	+	Showed several slides on the current status of the 2.5T packing fraction. Showed first a carbon slide showing better agreement, but still a few very jagged areas in the simulated carbon peak, and mentioned that he has defaulted to comparing dilution data with helium in it, as the optics data proved very hard to work with. J.P. mentioned that in addition to the jagged behavior at the top of the peak, it is worth looking into why the simulation peak seems wider than the production data very slightly at the base. Using the scale factor provided by this carbon comparison, David showed several slides of the resulting packing fractions, doing a linear fit to an 0.4 and 0.6 packing fraction simulated yield. J.P. and Karl gave several suggestions for dealing with the Helium elastic peak, since that has not been done yet. J.P. also suggested it was a good idea to take the whole Nitrogen peak when integrating to find the packing fraction, rather than just part of it. David mentioned he would also talk to Chao about the odd behavior at the top of the elastic peaks and ask for suggestions.  The packing fractions at this stage seem to give reasonable values, though everyone commented it will be important to subtract the Helium elastic peak before finalizing the packing fractions, and apply this same method to one of the 5T energy settings to compare to Toby's Ratio method.
−	The DAQ rate can go to 9k Hz in the pulse test. <br>	+
−	2) Found the pedestal threshold for ADC <br>	+
−	*Jixie, Min, Chao:	+	Verbal Updates:
−	1) Got some Hall-B coil drawings, also got a fortran routine to calculate the field from Peter Bosted. <br>	+
−	Click [https://hallaweb.jlab.org/dvcslog/g2p/135 here] to download them. <br>	+
−	2) Will add the geometry and field to the Geant4 modle <br>	+
−	3) Will have optics meeting tomorrow from 2:30 to 3:30 right after target meeting at A110. All is welcome to join.<br>	+
−	4) Finalize the synchrotron radiation at Chicane: when the photons energy reach 50keV, the rate drops below 1Hz. The<br>	+
−	photos came form the 1st magnet will not be able to hit the target because they are blocked by the 2nd magnet. Those <br>	+
−	photons came from the 2nd magnet will not hit the target neither.<br>	+
−	5) Still working on the bremsstrahlung radiation within the scattering chamber <br>	+
−	6) Min is running the simulation for optics <br>	+
−		+
−	*Pengjia, Jie:	+
−	1) working on installing the intel CPU with HSR DAQ <br>	+
−	2) Jie is test the ADC of HAPPPEX DAQ for Left and Right HRS <br>	+
−	*Ryan:	+	None
−	1) Checking preshower|shower to make sure it works. <br>	+
−	*Toby:	+	==09/13/2018==
−	1) Work with target group. Took HallB magnet chamber down and shipped to EEL building. Will cut it and take the <br>	+	Present: Chao, J.P., David
−	magnet out soon. <br>	+	'''Feature Presentations :
−	2) continue learning the G4 <br>	+
−	*Melissa:	+	None
−	1) check the preshower|shower using Xgt2 data. Found the one in right HRS have low efficiency(as low as 97%). Vince mentioned<br>	+
−	this could be due to the low electron momentum (~0.8 GeV). Melissa will check it with high energy data set. <br>	+
−	*Vince:	+	Verbal Updates:
−	1) Jack is working on adding a third Fastbus crate for left HRS.  When he finishes, Vince will work on checking the left HRS DAQ with the new crate.	+
−		+
−	----	+
−	<B>10/26/2011</B>:	+
−	Present: Karl, Jixie, Melissa, Min, Chao, Pengjia, Kalyan, Alex, Vince, Toby, JP, Aidan, Ryan	+
−	*Karl:	+	*Chao
−	1) There is an update to the G2P schedule. The start date of this experiment could be middle of Feb (not official date yet). <br>	+	Working on smoothing out the acceptance correction for the 5T Transverse 2.2 GeV energy setting.
−	We have to give up the 12.5 degree runnings. <br>	+
−	*JP:	+	*David
−	1) Discussed the g2p commissioning before the target is ready. We can do a lot of detector and DAQ test.<br>	+	Showed a few slides, indicating that the proper cuts give very good agreement for the carbon data in the elastic region. However, it was discussed that there are many jagged peaks above this region that Chao says should not exist. Chao gave a few suggestions for improving the simulation's agreement. David also asked about how to scale properly by the luminosity, and how to actually put the packing fraction in the simulation, as the setting in the simulation only changes the energy loss according to Chao. J.P. and Chao explained that David should just scale the 0.6 packing fraction simulation by 0.6, and so on, but that each element would need to be scaled separately and added together (so for 0.6 packing fraction, total yield = 0.6 Nitrogen + 0.4 Helium + 0.6 Proton, etc). J.P. also suggested to try simulating an empty cell as the helium peak should be clean and match well.
−	2) There will be 2~3 irradiation carried out at NIST. 3 students will go to learn and help. Pengjia and Toby <br>	+
−	will go. There 3 person could be rotated among students. Chao volunteer to go. <br>	+
−	*Kalyan, Chao:	+	==08/09/2018==
−	1) Test the 3rd arm detector with source (Cs137, average momentum is 150keV, maximum about 500keV). <br>	+	Present: Chao, Karl, David
−	2) 3rd arm stand is assembled in the hall. <br>	+	'''Feature Presentations :
−	3) keep working to the DAQ, need to find a way to subtract the pedestal in VME. <br>	+
−	4) Chao report [http://hallaweb.jlab.org/experiment/g2p/collaborators/chao/WeeklyMeeting10262011.pdf the calibration] <br>	+
−	*Jixie, Min:	+	None
−	1) Built chicane into the Geant4 simulation, see 3D plots [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20111026_Syncrotron/HRSMC_v0.98_p05/ here] <br>	+
−	2) Show the study about the synchrotron radiation at chicane. Here is a [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20111026_Syncrotron/SynchrotronRadiation.pdf document] about the details of synchrotron. <br>	+
−	According to our calculation, the radiation power of all beam energy at chicane magnet B1 is about 20~30 micro-watt.<br>	+
−	Jp suggested to calculate the rates for high energy photons which will tell if it will affect the physics result. <br>	+
−	3) Still working on the bremsstrahlung radiation at target chamber <br>	+
−	4) Min reported the [http://hallaweb.jlab.org/experiment/g2p/collaborators/mhuang/102611-opticsSimu.pdf optics status]. <br>	+
−	5) Pengjia told that we can use the slow raster to change the beam position during cross scan for optic runs. This will <br>	+
−	have only 5 minutes of change over, which can save lot of time. JP suggested to check with Yves Roblin about that. <br>	+
−	*Pengjia:	+	Verbal Updates:
−	1) Put ADC back to happex daq with voltage mode. <br>	+
−	*Ryan, Melissa, Vince:	+	*Chao
−	1) Working on the HRS DAQ.  <br>	+	Working on finishing transverse data, doing another replay, save root files on his local computer so it will not be diluted anymore, will calculate transverse acceptance soon. Won’t be at meeting next week, in two weeks will show final 5T 2.2 GeV transverse acceptance.
−	2) Bogdan agreed to fix the bad PMTs on the left HRS Cherenkov detector <br>	+
−	3) Bogdan requested 2 plots for lead glass: "pedestal vs channel" and "cosmic peak vs channel". Ryan will provide them. <br>	+
−	4) Vince set up a separate DB for the Right HRS CODA, which solves the platform interference problem. <br>	+
−	*Toby:	+	*David
−	1) Working with target group <br>	+	Working on comparison between carbon g2psim and data for 2.2GeV 2.5T, asked Chao a few technical questions about weighting the g2psim histograms in C++ or Python.
−	2) Learning the G4 program <br>	+
−		+
−	----	+
−	<B>10/19/2011</B>:	+
−	Present: Karl, Jixie, Jie, Melissa, Min, Chao, Pengjia, Kalyan, Alex, Vince, Toby, JP, Yuxiang Zhao, Yawei Zhang, Yi Zhou	+
−	*JP:	+
−	1) Update of the target:  2 places of short to ground found. Will need to open the coil package for deep <br>	+
−	diagnostics.  2 more weeks of delay is expected if we plan to fix the short to ground problem. <br>	+
−	2) Looking for feasibility of using the magnet of Hall B.  There is lot of constrain to use this magnet.  A delay of <br>	+
−	2 month will be expected if use it. <br>	+
−	*Karl:	+	==08/02/2018==
−	1)Readiness and safety review will take place next Monday, 1 PM. Everybody are welcomed to attend and <br>	+	Present: Chao, J.P., Karl, David
−	support us.  Check [https://hallaweb.jlab.org/wiki/index.php/G2p_safety_102411 here] for details. <br>	+	'''Feature Presentations :
−	*Toby:	+	*Chao
−	1) Presented the [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/10.19.11/scalers.pdf scaler map]<br>	+	Chao showed a few slides of final longitudinal acceptance correction, which he said look good except for a discontinuity at the start of the quasi elastic peak for longitudinal. Karl suggested checking the same plots with no dp cut just to compare. Chao also suggested that we make a repository of all g2p codes and simulations so that we can easily access whatever we need.
−	2) Determined the beam incline angles at target center for various settings using Geant4 program HRSMC with<br>	+
−	NEW target field. The vertical and horizontal offset of the beam at 1.1 meter away from the target center are also <br>	+
−	extracted. Check [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/G4%20Plots/ here] for figures. <br>	+
−	*Jixie:	+	Verbal Updates:
−	1) Presented some [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20111019_Readiness/ figures] prepared for the readiness review, including beam spot at local dump, 'flame of sheet', etc... <br>	+
−	*Melissa:	+	*David
−	1) Re-did the analysis for the HRS gas Cherenkovs.  Three channels in the left arm seem to have a low number of photoelectrons, <br>	+	David mentioned that he’s working on learning to use g2psim with Chao’s help, so that he can tweak it and produce simulated yields for use in the Oscar PF method.
−	check [http://hallaweb.jlab.org/experiment/g2p/collaborators/melissac/Cherenkov_Analysis.pdf here] for details.	+
−	Need to report to Bogdan and request for replacement. <br>	+
−	*Pengjia:	+	==07/26/2018==
−	1) Reported the HAPPEX DAQ status.  Check his [https://userweb.jlab.org/~pzhu/report/Happex%20DAQ%20Status%2010.18.2011.pptx talk] for details.	+	Present: Chao, Karl, David
		+	'''Feature Presentations :
−	*Vince:	+	None
−	1)  Figured out the reason for CODA interference of left HRS and right HRS.  The platform uses an account name to identify <br>	+
−	the database.  Both the left and right HRS use the same database name: adaq.  Therefore killing the right HRS platform will also <br>	+
−	disconnect the left HRS run control.  The solution is to change the user account for the platform to run the right HRS DAQ.	+
		+	Verbal Updates:
−	----	+	*David: thanked Chao for sending g2psim, asked a few technical questions about operating it. Chao noted that it’s important to run each material seperately, so for production data, to run nitrogen, hydrogen, and helium independently and convolute them. David also showed the functional form of the uncertainty in g2 as a function of the uncertainty in the packing fraction, Karl suggested to provide rough numerical values and David agreed to do so next week.
−	<B>10/12/2011</B>:	+
−	Present: Karl, Jixie, Jie, Min, Chao, Pengjia, Kalyan, Vince, Toby, JP, Yuxiang Zhao	+
−	*Karl:	+
−	1) In order to improve students' skill of doing presentation, we will have 2-3 students each week to give <br>	+
−	feature presentation about what they are doing in the part weeks. <br>	+
−	2) Latest schedule can be find [https://hallaweb.jlab.org/wiki/index.php/G2p#Runplan.2FSchedule here]<br>	+
−	*JP:	+	*Chao: Sent David the current working version of g2p sim, very nearly done with 5T longitudinal acceptance. Will show cross sections for 5T longitudinal next week.
−	1) Target status update: <br>	+
−	A) There is enough space to put the sodium pad into the coil container <br>	+
−	B) Found about 2~3 short grounded place in the coil. Not clear if can fix them all. Waiting for suggestion from Oxford<br>	+
−	C) Try to get Hall B Helmholtz coil and make it work for the experiment in the meanwhile (2 magnet are prepare in parallel).<br>	+
−	2) Running schedule have been officially changed to Dec. 1st <br>	+
−	3) 2-channeled BPM has been tested in hall C and works now. 4-channeled BPM is expected to finish design in 2 more weeks.<br>	+
−	*Jixie, Min:	+	==07/19/2018==
−	1) A preliminary draft of optics plan can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/mhuang/OpticsRate2.pdf here], still need to run more simulation to check some items <br>	+	Present: Chao, J.P., Karl, David
−	2) Jixie is working on the simulation for bremsstrahlung photons and other safety review related items <br>	+	'''Feature Presentations :
−	*Vince, Ryan, Melissa:	+	*Karl
−	1) Ryan gave a nice report of the DAQ status, check [http://hallaweb.jlab.org/experiment/g2p/collaborators/rbziel/DAQ_STATUS.pdf here] <br>	+	Karl started off with some overview slides to try and get a majority of the work done by the end of the summer before people get busy. He voiced that the biggest question is whether we are using a data or model cross section, where the data is the attractive option if possible to make our results model independent, but the model may be a better option if the data is impossible or will take too long, as we can more or less publish the 5T data now, and the 2.5T data (pending pf analysis)
		+	He also asked if by the end of the meeting, we could identify all outstanding tasks and give an estimate for how long they will take to complete. Barring december, said that we should plan to have a paper submitted to PRL by the end of the year.
−	*Pengjia, Jie:	+	Moments paper work to be done yet: Low x contribution to BC integral
−	1) optimizing the HAPPEX ADC module <br>	+	Low nu contribution to gamma0
−	2) The "buffer full" issue in the HAPPEX DAQ is suddenly gone after recalling. The reason is not figured out yet.<br>	+
−	*Toby:	+	*David
−	1) Finished the scaler <br>	+	David showed a talk describing the Oscar Rondon packing fraction method. J.P. voiced that since the method requires scaling the simulation to carbon data, it cannot be used in the elastic region since you would need a different scale factor for carbon or nitrogen, so the only region to apply the method is the very inelastic one. Chao said right now he doesn’t think the simulation can do inelastic data, but that once he applies Ryan’s tweaked Bosted model, he thinks it will be able to. There was some discussion about the error bar for this packing fraction method, and J.P. said that the standard deviation of both the carbon and the production data in the chosen region would need to be applied to get the total error.
−	2) Worked with Pengjia in optimizing the TDC which is using an Intel CPU <br>	+
−	3) Learning the geant4 program <br>	+
−	*Kalyan, Chao:	+	There was brief discussion of going back to the unfinished elastic fit method if all else fails, since all that should need to be done is finding a way to deal with quasi elastic contamination.
−	1) Test E plane PMTs with cosmic rays, check the details [http://hallaweb.jlab.org/experiment/g2p/collaborators/chao/E_CosmicRay.pdf here]	+
		+	David also showed plots for the scattering angle for 2.5T 2.2GeV that show that even once the materials are separated out, all the data seems choppy at high E’ values.
−	----
−	<B>10/05/2011</B>:
−	Present: Karl, James, Jixie, Jie, Melissa, Min, Chao, Pengjia, Kalyan, Aiden, Vince, Toby, JP, Yuxiang Zhao, Yawei Zhang, Yi Zhou, Zhao Zhang
−	*Karl:
−	1) Welcome James joining g2p! James will working on the target related projects for this experiment <br>
−	2) Latest schedule is available [https://hallaweb.jlab.org/wiki/index.php/G2p#Runplan.2FSchedule here]<br>
−	3) Encourage all users to upload documentation to this [https://hallaweb.jlab.org/wiki/index.php/G2p#Documentation location] <br>
−	*James:	+	Verbal Updates:
−	1) Got permission from Oxford that the target coil can be cut and opened for investigation. The coil <br>	+
−	is now in machine shop. <br>	+
−	2) Will work on target operator training procedure and put it on the wiki. Will also arrange target <br>	+
−	operator training sessions. <br>	+
−	*Kalyan, Chao:	+	*Ryan
−	1) Finished gain match (HV adjusting such that each PMT will have the same peak location) for dE planes using <br> cosmic ray, will do this to the E planes. <br>	+	Finally, David relayed a few questions from Ryan. Karl said he doesn’t care which paper is published first and we should just publish them in the order we are able to. He also voiced that Ryan’s hyperfine question was something we could discuss offline or at the next meeting as time ran short. With regard to the question of using our cross sections, the eventual conclusion was that if Chao is able to match the timetable he provided today that it may be feasible to use g2p cross sections for all 2.2GeV energy settings.
−	2) Try to optimize the DAQ rate to reach 10k Hz. <br>	+
−	3) Will do the OSP for the 3rd arm. <br>	+
−	4) Show the dE planes gain match result [http://hallaweb.jlab.org/experiment/g2p/collaborators/chao/dE_ADC.pdf here]. <br>	+
−	*Jixie, Min:	+	*Chao
−	1) Run elastic simulation with C12, CH2, LHe and Al targets for all possible combination configurations of <br>	+	Chao says within 2 weeks he can get cross section for longitudinal. Estimates within 1 month will have acceptance for 2.2 GeV, 5T Trans+Long, and another 6 weeks for 2.2GeV, 2.5T Trans. He said that 3.4 GeV has no elastic so he’s not sure there will be an acceptance. Karl and JP suggested he then prioritize the three 2.2GeV settings.
−	beam energies, target field and HRS angles. Calculate the elastic rates for w/o sieve. Also calculate rates for<br>	+
−	some single sieve holes.  Check the details [https://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20111004_Optics here]. <br>	+
−	2) The 1st draft of the optics plan is [http://hallaweb.jlab.org/experiment/g2p/collaborators/mhuang/OpticsRate.pdf here]. <br>	+
−	In this draft, no changing time is considered yet. Will improve this draft and update it. <br>	+
−		+
−	*Vince, Melissa, Ryan, Toby:	+
−	1) Problem of CODA script: killcoda on adaql1 will also cause the run on adaql2 to end, need to find the reason <br> and solve it. <br>	+
−	2) After installing an Intel CPU in ROC 1, the right HRS does not get any triggers. Vince will help Ryan and Pengjia <br> investigate it after the meeting.<br>	+
−	3) Ryan reported the S1 bad PMTs to Bogdan. Some more figures were requested to prove these PMTs are really bad. <br> He will generate figures for that. <br>	+
−	4) Melissa will redo the fit to Cherenkov NPHE with new fitting function (Gaussian+Poisson). She has also redone the <br> fits for the SPE.  With the improved analysis the NPHE will be higher than previous fit. <br>	+
−	5) Toby is working on scalers. He needs to verify their connections to both HRS and make sure they work including the <br> helicity-gated scalers. <br>	+
−	*Jie:	+	David estimated 6-7 weeks to get the packing fraction assuming we can get simulated yields. Chao agreed to send g2p simulation package to David so he can help with adding in missing models (Ryan Bosted-tweak?) and start learning to use it for applying the Oscar Method.
−	1) The 2nd version of [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2011_10_05_fieldmap_report/Target_Field_Map_Report.pdf field analysis note] is ready for review. <br>	+
−	*Pengjia:	+	==07/12/2018==
−	1) Connecting HAPPEX crate to Left HRS, (not finish yet) <br>	+	Present: Chao, J.P., Karl, Ellie, David
		+	'''Feature Presentations :
		+	*Karl
		+	Showed the plots that he showed at Trento, and mentioned that there is a lot of interest right now specifically in the hyperfine result, as Ryan's calculation of delta 2 disagrees noticeably with the most recent papers. Said that we should try and get the paper out by the end of the year, so we should try and finish both acceptance and pf by the end of summer. Suggested that next week we sit down to figure out a game plan for how to do that.
−	----	+	Verbal Updates:
−	<B>9/28/2011</B>:	+
−	Present: Karl, Jixie, Jie, Melissa, Min, Chao, Pengjia, Kalyan, Alex, Vince, Toby, JP, Yuxiang Zhao, Yawei Zhang	+
−	*Karl:	+
−	1) Target coil quench protection part will be opened today or tomorrow for investigation.	+
−		+
−	*Kalyan, Chao:	+
−	1) 3rd arm daq: have 1 ADC and 1 TDC working so far. Working on the scaler right now. Will make a copy <br> of ADC and TDC for backup. <br>	+
−	2) Tested the dE plane ADC signal with cosmic ray. The trigger is the coincidence of 2 dE planes. The <br> [http://hallaweb.jlab.org/experiment/g2p/collaborators/chao/ADC.pdf figure] shows that PMTs in the left<br> have narrower signal compared to those in the right.  Need to check reasons for that.  <br>	+
−	*Jixie, Min:	+	*David
−	1) Updated the Gean4 program HRSMC to support titled beam simulation. A uniform field model have been<br> coded to correct the incident angle of the incoming electron. The effective scattering angle will be<br> calculated and the elastic scattering energy then will be determined based on the effective scattering<br> angle. Here is a [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20110928_SieveSlit/HRSMC_v0.98.png picture] of current version.<br>	+	Mentioned that he and Karl got in touch with Oscar Rondon to ask a few questions about his packing fraction method, which we hope to try. Also said that he is currently re-playing the packing fraction rootfiles for several gradations of cut in case we want to study the cut dependence of the ratio method. Also working on producing plots for the scattering angle fit for just the carbon data, and for each production material independently. Karl asked Chao about how good the simulation is for the transverse settings, Chao said he has been focusing on the simulation for the 5T 2.2GeV settings but could maybe look into it.
−	2) Simulated the elastic events with C12, CH2 and liquid Helium target with sieve slit in position. <br>	+
−	50 mil, 100 mil and 200 mil thick of C12 have been simulated. Check details [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20110928_SieveSlit/ here].<br>	+
−	The result shows that for 1.2 GeV beam, elastic peak of C12 will be overlapped with that of helium.<br>	+
−	3) Considering the fact that the uncertainty of deltaP between H peak and C peak is dominated by H peak, <br>	+
−	(in other words, the overlap of C peak and He peak will not be the major source of uncertainty), we <br>	+
−	will not warn up the target during optics.  <br>	+
−	4) The optics plan is still under discussion. Min is working on snake and mudifi to verify the plan. <br>	+
−	Min also show a few [https://hallaweb.jlab.org/wiki/index.php/Image:OpticsII-0928.pdf slices] about that. <br>	+
−	5) G2P work disk will be upgraded to 1T space from 14:30.	+
−	*Jie:	+	*Chao
−	1) Work with Pengjia on HAPPEX DAQ project.<br>	+	Chao said he is continuing to work on the acceptance, and has been looking into the super-elastic peak J.P. asked about last week.
−	2) HAPPEX crate has been merged with the right HRS DAQ.	+
−	*Vince, Ryan, Melissa:	+	==05/31/2018==
−	1) Took cosmic data for the left and right HRSs. <br>	+
−	2) Left HRS, checked S1 PMT signals for after-pulsing issue. About four PMTs have a large amount of after-pulses, bars 5 and 6. <br>	+
−	3) Found that the ADC amplitude of some of the PMTs is very low. Will compare to cosmic data in the Spring to find out if the low amplitudes existed then. <br>	+
−	4) Initial conversation with Bogdan resulted in him requesting more plots for the ADC amplitudes. Melissa is making those plots now.<br>	+
−	5) We probably need to replace the PMTs.  However, Bogdan only has about half the PMTs for both S1 detectors (left and right). <br>	+
−	(Those PMTs are out of production, we may need another solution.) <br>	+
−	Check the details [http://hallaweb.jlab.org/experiment/g2p/collaborators/rbziel/s1_pmt_check.pdf here].<br>	+
		+	Present: Chao, J.P., Karl, Ellie, David
		+	'''Feature Presentations :
−	*Toby:	+	*Chao
−	1) Working on the coda scripts. <br>	+	Fit correction to the yield for 7 momentum settings in quasielastic region. Checked if the correction is stable and showed plot of yield for a 2.2GeV 5T run with the correction applied. J.P. says effective correction should be fine to fix relative difference. Discussed discontinuity at nu = ~459 MeV, Chao said he can fit that region to try and remove it. Karl asked about the motivation for the correction, Chao explained it is a fit that he found that works. See agendas section for plots.
−	2) Updated the root to version 5.28 in the farm for analyzer. Ole has updated the root for adaq machines<br>	+
−	to 5.30. Toby will update the root to this version too. <br>	+
−	*Pengjia:	+	Verbal Updates:
−	1) HAPPEX DAQ works for right HRS. Working on making another copy to left HRS.  Will check the dead <br>	+
−	time on the HRS DAQ due to adding the HAPPEX crate	+
−		+
−	----	+	*David
−	<B>9/21/2011</B>:	+	Still trying to work on packing fraction analysis. Modified code from Toby to re-add 5T settings, can nearly reproduce Toby's results but scaled down by a factor of 3.5 for all 5T energy settings. Sent an email to Toby and trying to look into what variable change could cause this difference between 2.5T and 5T.
−	Present: Karl, Jixie, Jie, Melissa, Min, Chao, Pengjia, Kalyan, Alex, Vince, Toby, JP, Yuxiang Zhao, Yi Zhou, Zhao Zhang	+
−	*Pengjia:	+	==05/24/2018==
−	1) Copied HAPPEX DAQ (HARDWARE) into the right HRS and got it work. <br>	+
−	2) Tungsten colorimeter is still under testing by Arne's student. We was told <br>	+
−	that it need two more weeks to finish.<br>	+
−	3) Show a few [https://userweb.jlab.org/~pzhu/report/Helicity%20setting.pptx slices] about the helicity signal that will be used during in g2p.<br>	+
−	*Kalyan:	+	Present: Chao, J.P., Karl, David
−	1) Working on 3rd arm DAQ. It is basically working right now. Doing the test with dE plane. <br>	+	'''Feature Presentations :
−	2) Worked with Whit(Engineering group) to design the support of the magnetic shielding.  <br>	+
−	The shielding material has been ordered. <br>	+
−	*Jixie:	+	None
−	1) Working on the simulation of C12, LHe, CH2 and LH2 with sieve slit in position.  Trying to finish <br>	+
−	the reconstruction code and verify if the we can separate the elastic peak of C12 from that of LHe. <br>	+
−	Check [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20110921_SieveSlit here] for details.	+
−	This [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20110921_SieveSlit/SieveHole33_5.69deg_E1.159_combined.png figure] shows the CH2 elastic peak at 1.159 GeV beam energy. <br>	+
−	The momentum elastic peak of helium and Carbon start to overlap after energy loss. Note that the momentum are not <br> reconstructed momentum.  Smeared be the VDC resolution and reconstruction resolution, these 2 peak will overlap even more. <br>	+
−	*Min:	+	Verbal Updates:
−	1) Working on mudifi to fit Geant4 sieve slit data for target field reconstruction routines<br>	+
−	2) Tuning the snake field map <br>	+
−	*Jie and Toby:	+	*Chao
−	1) The target field measurement with translation table [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2011_09_21_fieldmap/Target_Field_Map_Report.pdf analysis note] is ready for group review. <br>	+	Still working on data corrections for the acceptance discontinuity, will have results next week. Also looked into beam position and found how to retrieve data from EPICS to help David, though warned that this does not give the real beam position, but the beam jumps should still show up in the raw data.
−	2) The target field measurement on can surface [https://hallaweb.jlab.org/dvcslog/g2p/131 analysis note] is also ready for group review. <br>	+	*David
−	Toby also show some figure [http://hallaweb.jlab.org/experiment/g2p/collaborators/tbadman/g2p%20meetings/09.21.11/finalreport.pdf here.]	+	Working on packing fractions and the to-do list of suggestions Ryan left last week, is able to reproduce Toby's ratios, working on doing a fit to the scattering angle to determine how the simulation might change with the tighter cut. J.P. suggested that taking the average scattering angle required correcting the data to an average as well. David also mentioned that he fixed the issue with getting null results from Toby's code for 5T, but still cannot reproduce the 5T packing fractions correctly.
−		+
−	*Melissa, Vince and Ryan :	+
−	1) Working on HRS DAQ. The DAQs for both arm are basically working. <br>	+
−	2) Melissa Updated start_coda script such that it starts left HRS DAQ on adaql1 and right HRS DAQ on adaql2<br>	+
−	3) Took cosmic run with left HRS. Will take cosmic run for right HRS soon. <br>	+
−	4) One rack keep losing power, Jack will take care of that <br>	+
−	5) A couple HV channels were tripping for S2m, the HV card was suspected and replaced. <br>	+
−	6) Ryan also looked into S1 and S2m TDC signal, some channels looks abnormal.	+
−	Need to spend more time checking that. <br>	+
−	*Chao:	+	==05/17/2018==
−	1) Working on 3rd arm DAQ with Kalyan. Will do pedestal run soon.	+
−	2) Measure the sieve slits for hole positions. They are all match the design.	+
−	*Alex:	+	Present: Chao, J.P., Karl, David
−	1)Working on test the intel CPU in DAQ.	+	'''Feature Presentations :
		+	None
−	----	+	Verbal Updates:
−	<B>9/14/2011</B>:	+	*David
−	Present: Karl, Jixie, Jie, Melissa, Min, Chao, Pengjia, Kalyan, Alex, Vince, Toby	+	Showed a few plots of the spread and average for each momentum setting involved in the asymmetry discrepancy analysis for the 2.5T data. However, J.P. noted that some of the means didn't quite make sense given the error bars of the points involved, and it became clear that there were a few mistakes in the normalization of the parameters for these plots. Further, differences between the global run by run asymmetry plot and the momentum-setting ones lead to the conclusion that there must have been a mistake in the presentation of the plots. David said he would re-do this section of the analysis more carefully and try again next week to determine if any of the momentum settings seem pathological.
−	*Kalyan:	+	==04/26/2018==
−	1) Working on 3rd arm DAQ with Chao <br>	+
−	2) The magnetic shielding (netic cylinder + co-netic foil) order has been placed <br>	+
−	*Jixie:	+	Present: J.P., Karl, David
−	1) Shift schedule is ready to sign. Called for checking the description. Karl suggested not to <br>	+	'''Feature Presentations :
−	open the 2nd period for user now. For those who have signed shifts in the 2nd period we will honor <br>	+
−	them the shifts they signed. <br>	+
−	2) Working on the TOSP for septum field mapping <br>	+
−	3) Compare SANE TOSCA map with our NEW TOSCA map together with Oscar. Could not find the reason. <br>	+
−	4) Running simulation to check optics plan <br>	+
−	*Alex:	+	None
−	1) Try to use intel CPU to replace the CPU board. 6~10 kHz DAQ rates is expected. <br>	+
−	*Vince:	+	Verbal Updates:
−	1) Working on HRS DAQ with Melissa and Ryan; Roc3 is now not running <br>	+
−	2) Check the lumi HV crate, one channel keep tripping off. (Nothing we can do so far) <br>	+
−	3) Plan to change the Left HRS HV operation interface as the one used for the right arm. <br>	+
−	*Min:	+	*David
−	1) Prepare for optic plan <br>	+	Showed a reprisal of his update on the Left and Right HRS Asymmetry comparison for the 2.2 GeV 2.5 T data to catch J.P. up, and mentioned that he will produce a plot of total asymmetry plotted against run number by using a run by run asymmetry, at Ryan's suggestion. J.P. and Karl both agreed that it would not be wholly unacceptable to add a systematic to the moment data if the issue could not be resolved otherwise, but that it would be ideal to solve it and not have to do that. J.P. also suggested that since the asymmetry seems to be unstable for both arms around the relevant point, that perhaps something happened with the beam, and suggested cross comparing to Jie's BPM analysis to try and determine if there was a beam jump or something similar around the time that the inconsistency occurs.
−	2) Working with Pendjia for helicity signal in the HAPPEX DAQ <br>	+	Also showed a table of packing fractions generated from Toby's scripts with different acceptance cuts. Said that the inclusion/exclusion of the RunStatus 6 Packing Fraction runs seems to have little impact on the Packing Fractions generated, but that using Ryan's tight cut in place of any of Toby's loose cuts produces packing fractions for the 2.2 GeV 2.5 T setting that seemed to Karl to be more reasonable. J.P. and Karl both suggested that one standard cut should be used for everything, preferably Ryan's tight cut since that has been well documented and discussed already. David said he will produce a re-done version of Table 6.4 from Toby's thesis, with all of the packing fractions generated using Ryan's tight cut.
−	*Jie:	+	==04/05/2018==
−	1) Writing tech note for field measurement with translation table <br>	+
−	2) Working with Pendjia for helicity signal in the HAPPEX DAQ. Made a [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2011_09_14_DAQ/Delay_time.pdf comparison] of time delay for	+
−	3 modeules. <br>	+
−	*Melissa:	+	Present: Chao, David
−	1) Show the pre-shower|shower analysis [http://hallaweb.jlab.org/experiment/g2p/collaborators/melissac/preshower:shower%20calibration.pdf result]. <br>	+	'''Feature Presentations :
−	*Ryan:	+	None
−	1) Working on left HRS ROC3. Took the structure fastbus interface from BigBite, but it does not work in roc3. <br>	+
−	Will try to use an old CPU. <br>	+
−	*Toby:	+	Verbal Updates:
−	1) Updated the G2p  wiki with README (instruction) for replay <br>	+
−	2) Writing the tech note of the target field measurement on the can surface <br>	+
−	*Pengjia:	+	*Chao
−	1) Tested the dead time for various DAQ configurations. Check Elog entry [https://hallaweb.jlab.org/dvcslog/g2p/129 129] for details. <br>	+	Still working on trying to resolve acceptance issue, before J.P. left for China he advised that Chao try cuts on various variables that go into the acceptance, like the Raster and the BPMs, to try to quantify what the effect on the acceptance is. Chao said he is currently working on doing this.
−	*Chao:	+	*David
−	1) Working on 3rd arm DAQ with Kalyan<br>	+	Said that he compared error bar on Gamma 2 to the variation in Gamma 2 caused by the discrepancy in the asymmetry between the left and right arms for the 2.5T 2254 MeV data, and that the total errorbar (statistical+systematic) is about 33% of the value of the moment, while the discrepancy causes a 20% change, for comparison. Also discovered that Toby's rootfile code appears to produce root files formatted differently from the ones his packing fraction script calls so working on eliminating the differences so that they can actually run together.
−	2) Glued the broken dE plane scintillator <br>	+
		+	==03/29/2018==
−	----	+	Present: Karl, David
−	<B>9/7/2011</B>:	+	'''Feature Presentations :
−	Present: Karl, Jixie, Jie, Melissa, Min, Chao, Pengjia, Kalyan, JP, Alex, Vince,Toby, Yi Zhou, Yuxiang Zhao	+
−	*Karl:	+	*David
−	1) The draft of run schedule is available [https://hallaweb.jlab.org/wiki/index.php/G2p#Runplan.2FSchedule here].  <br>	+	Presented an update on the 2.5T 2254 MeV data asymmetry comparison, showing the result of replaying the data with a tighter momentum cut. Unfortunately, the tighter momentum cut seems to worsen the chi^2 comparison rather than improve it. Also showed and discussed with Karl an attempt to determine how serious the effects of the asymmetry discrepancy are on the final value for Gamma 2. The discrepancy seems to be responsible for a 20% variation in Gamma 2, but Karl said this value should be compared to the size of the existing error bar to determine if just throwing a systematic on and using the original data would be a valid way to go. Also re-showed the comparison of data taken on the first sweep up the momentum spectrum to data taken going back down, and showed that the largest discrepancy only occurs on the second set of runs, though no glaring change is notable in the log book.
−	2) Discuss the safety and OSP|TOSP document issues	+
−	*JP:	+	David also mentioned that he's started work on trying to replay Toby's root files to re-generate the packing fractions for the 2.5T data.
−	Welcome 2 USTC visiting scholar Yi Zhou and Yixiang Zhao. They will work on GEM and SOLID projects.<br>	+
−	*Jixie:	+	Verbal Updates:
−	1) Agree to work on the TOSP for septum <br>	+
−	2) Discuss the shift schedule and related things. Collaborators need to take 10 shifts to fulfill<br>	+
−	the authorship requirement.  Collaborators is not allowed to take TO shifts until got trained or<br> agree to receive the TO training well before shift starts.  <br>	+
−	3) Will talk to Oscar to find out the difference between old TOSCA and new TOSCA map for the target field. [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20110907_ThirdArm/targetfile_cmp.png Here] is the figure showing the difference between these models.<br>	+
−	4) Design the magnetic shielding for the 3rd arm PMTs. Need to block 70 gauss field. Current chosen thickness, 0.062 inch, is over designed. <br>	+
−	*Min:	+	None
−	1) Reading tech notes and thesis. Prepare for optic plan.	+
−	*Kalyan:	+	==03/23/2018==
−	1)Remind the student that helicity signal in the HRS is delayed <br>	+
−	2)Setting up DAQ crate for the 3rd arm <br>	+
−	3)Working on the magnetic shielding  <br>	+
−	*Jie:	+	Present: Chao, David
−	1) Show his field analysis [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2011_09_07_fieldmap/ result]	+	'''Feature Presentations :
−	*Toby:	+	*Chao
−	1) Not finalize his field analysis result yet, will show the result later	+	Trying to resolve the issue Ryan discovered with acceptance not being continuous for production runs, using Dummy run to try and look at background and subtract out the effects of the target cell itself, runs are scaled by live charge so are proportional to cross section, so can be subtracted. This subtraction removes everything outside the target cell, effectively, the background, but does not consider the difference between foil target and extended target. Cut simulated target into 1mm slices to investigate-- for real target, there is no cross section difference between z=0, z=-13, and z=13, for any kinematic variable. Chao's conclusion is that either simulation doesn't match well, *or* the acceptance should not be dependent on the z position in the target. See slides attached to agendas section.
−	*Melissa:	+	Verbal Updates:
−	1) Looking into the HRS s1 & s2m TDC, check Elog [https://hallaweb.jlab.org/dvcslog/g2p/128 entry 128] for details <br>	+
−	2) Check the Cherencov TDC spectrum, see Elog [https://hallaweb.jlab.org/dvcslog/g2p/127 entry 127] for details <br>	+
−	3) Still working on checking shower|preshower TDC <br>	+
−	*Chao:	+	*David
−	1) working on 3rd arm simulation<br>	+	Left arm replay finished and asymmetries regenerated for 2.5T 2.2GeV runs, ran into issue with many of the right arm runs failing repeatedly on the batch farm. Going to try running interactively with Screen and using a different queue to avoid timeouts.
−	2) working on 3rd arm SC, made a holder and will glue it at the rest of this week<br>	+
−	*Pengjia:	+	==03/09/2018==
−	1) Ring buffer for HAPPEX DAQ works for helicity signal in the left arm. Will work on the right arm soon	+
−		+
−	----	+	Present: Ryan, J.P., Karl, David
		+	'''Feature Presentations :
−	<B>8/31/2011</B>:	+	None.
−	Present: Karl, Jixie, Jie, Melissa, Min, Chao, Pengjia, Kalyan, JP, Alex, Vince	+
−	*Jixie:	+	Verbal Updates:
−	1) Working on optics plan with Min. Need to recalculate e-C and e-H elas rates for 5.7 deg 2.5T. <br>	+
−	2) Confirm septum polarity before Howard connect it to the power supply <br>	+
−	3) Will perform B vs I curve for septum in middle Sep.  Chao and Min will join, Toby too. <br>	+
−	4) Karl suggest get (from Doug) the long cable which is used to connect to the hall probe. <br>	+
−	5) Will simulate what thickness will be good for a mu-medal to shield low energy protons. <br>	+
−	*Kalyan:	+	*Ryan
−	1) Working on the 3rd arm DAQ with Chao. <br>	+	Still waiting on Chao to get back to him about cross section issue, said Chao's explanation makes sense to him. J.P. asked about question dealing with the Y acceptance, but Ryan commented that he hasn't talked to Chao about it yet. Ryan agrees that the target length is the only thing different between carbon and production runs and that this is likely the source of the cross section issue.
−	2) The dE plane of the 3rd arm is 6'(width) x 12'(height) in size, not 12 x 12. This is found <br>	+
−	after it was opened. Chao will need to peel off the remainder glue and reglue it.  Jixie will <br>	+
−	check with Al about this change. <br>	+
−	3) Kalyan agree to following replacing PMT for S1L2 (check minutes of Aug. 17 for detail). <br>	+
−		+
−	*Vince:	+
−	1) Will join G2P and work on HRS DAQ. A 3rd crate might be added in order to improve DAQ rates. <br>	+
−	2) Will following the issue of HV crate of Lumi. (check  minutes of Aug. 17 for detail). <br>	+
−	*Min:	+	*David
−	1) Working on optics plan with Jixie.<br>	+	Replay finally working, ran into issue with some of the files coming out un-filled from the batch farm, but this is an issue Ryan has seen before and Ryan advised that he replay just the failed runs repeatedly until all of them function.
−	*Chao:	+	==11/27/2017==
−	1) Working on the 3rd arm DAQ<br>	+
−	2) open the SC with Kalyan. Will clean the opened SC and glue it back tomorrow<br>	+
−	3) Need to run the simulation again for the 3rd arm using 6x24 size and latest design positions.<br>	+
−	*Melissa:	+	Present: Ryan, Ellie, J.P., Karl, David
−	1) Checking on shower preshower. She will post her results to the elog.	+	'''Feature Presentations :
−	*Pengjia	+	None.
−	1) Make a [http://www.jlab.org/~pzhu/report/Happex%20DAQ%20for%20g2p%20experiment.pptx presentation] about the DAQ plan for BPM|BCM. <br>	+
−	After discussion we all agreed to put hardware into both left and right HRS crates such that each arm will have	+
−	a complete DAQ system. <br>	+
−	*Jie:	+	Verbal Updates:
−	1) Report that our measurement of the target field agree with the NEW tosca model with 1%. <br>	+
−	Check his results [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2011_08_31_fieldmap/field_map.pdf file1] [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2011-08-24_fieldmap/2011-08-24-fieldmap.pdf file2]. <br>	+
		+	*Ryan
		+	Discussed progress on the PRL with Karl and J.P., and whether or not the acceptance should be included.
		+	==11/17/2017==
−	----	+	Present: Ryan, Ellie, J.P., Karl, David
		+	'''Feature Presentations :
−	<B>8/24/2011</B>:	+	None.
−	Present: Karl, Jixie, Jie, Melissa, Ryan, Toby, Kalyan, JP, Chao, Min, Pengjia	+
−	*Jixie:	+	Verbal Updates:
−	1) The tosca model from SANE group was proved to be different from the one Robin recently <br>	+
−	created. Check [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20110824_TgFieldAna/Helm_OldVsNew.png  this plot] to see how they vary. Both the field analyses from Jie and Toby also confirm that. Jixie will <br>	+
−	talk to Robin to verify this.  <br>	+
−	2) Working on the Optics with and Min. A discussion with Jin Huang is ongoing. <br>	+
−	3) The 3rd arm design is done. Karl mentioned that Al might have some small change in the design of <br> of the stand. Jixie will check this with Al. <br>	+
−	4) Jixie will check the neutron background with the shielding with Poval. <br>	+
−	*Pengjia:	+	*Ryan
−	1) Got some progrss on the HAPPEX DAQ:  <br>	+	Corresponding about Hyperfine results with Franziska Hagelstein, got numbers for delta_1 and delta_2, Karl suggested that this is good but evidence that since Ryan's data is on the Arxiv, people are going to want to use it and this is more incentive for us to be expedient in getting to publish. Ryan is working on finishing the hyperfine paper and intends to include both 2.2 GeV 2.5 T data, and the g1 point.
−	A) The ring buffer works with helicity signal now, will move on to ADC signal  <br>	+
−	B) Still working on the TCPIP program <br>	+
−	2) Compared the BPM|BCM signal of HAPPEX DAQ and that from the scaler. It looks like HAPPEX DAQ give <br> better resolution. Pengjia, Kalyan, Alex and Bob will make the final decision which one to choose. <br>	+
−	3) Arne's student is testing the tungsten colorimeter with an external heat source in the Hall. Pengjia	+
−	is watching on this.	+
−	4) There are 2 options to put BCM|BPM signal into the data stream: <br>	+
−	option A: use socket program to insert the signal into the ET ring; <br>	+
−	Option B: integrate the hardware into HRS crate; <br>	+
−	Pengjia will compare these 2 options then make a choice.<br>	+
−	*Min:	+	*Karl
−	1) Working on the optics. Join the discussion with Jin and Jixie. See her report	+	Has approved Toby's thesis, after edits that provide more detail on the choice of the ratio method over the fit method for the packing fractions.
−	[https://hallaweb.jlab.org/wiki/index.php/Image:24082011.pdf here]	+
−	*Jie:	+	*David
−	1) Show the difference between old tosca map and new tosca map of the target field. Also show the	+	Still working on tight dp cut replay, has all of Toby's dilution and packing fraction scripts running locally, Ryan and Karl suggested trying to replay dilutions with a tighter acceptance.
−	field analysis result. [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2011-08-24_fieldmap/2011-08-24-fieldmap.pdf Check details here]. <br>	+
−	*Toby:	+	*Chao
−	1) Showed his field analysis [http://hallaweb.jlab.org/experiment/g2p/collaborators/tbadman/g2p%20meetings/8.24.11/results.pdf result] using the new target field. The current ratio from his result <br>	+	Trying to get acceptance study running on JLab batch farm. Longitudinal study for the acceptance is done.
−	is consistent with Jie's result. But the position offsets still have some difference. <br>	+
−	*Chao:
−	1) Writing a tech note about the design of the 3rd arm with Jixie <br>
−	*Ryan:
−	1) installed S1 back to HRS, will connect the cables and DAQ <br>
−	*Melissa:	+	==10/27/2017==
−	1) Practice the calibration of shower and pre-shower using xgt2 data <br>	+
−	*Kalyan:	+	Present: Ryan, Ellie, J.P., David
−	1) Confirm that the trigger has been settled as the way we discussed in last meeting <br>	+	'''Feature Presentations :
−	2) Confirm that the 3rd arm DAQ can go up to 10KHZ <br>	+
		+	*Chao
		+	Acceptance study for the longitudinal settings is just about finished. Elastic peak agrees well with theory, continuity of nu spectrum is good. Needs a conversion between slow and fast raster current. Transverse spectrum has not as good continuity, will be fixed soon.
		+	Verbal Updates:
−	----	+	*David
		+	Still working on tight dp cut replay, showed proof of principle doing dp cut on bin by bin basis, that seems to give more evidence that this is the issue, but aims to make it better with the count by count replay.
−	<B>8/17/2011</B>:	+	*Karl
−	Present: Karl, Jixie, Vincent, Jie, Mellisa, Ryan, Toby, Doug, Alex, Kalyan, Zhihong<br>	+	Showed plots of g2p packing fractions vs SANE packing fractions, discussed the elastic fit method with Toby to determine that the .3 packing fraction is not good, but wants to investigate the suspiciously high 2.5T packing fractions, since SANE data never goes above .74.
−	By Phone: Chao, Pengjia, Min	+
−	<B>Discussion about the trigger</B>	+	==10/06/2017==
−	*Zhihong, Karl, Doug, Alex, Vince ... : <br>	+
−	1) The HV of 3 channels in the  (Left?) Cherencov  are too high, need to be adjusted; <br>	+
−	2) According to xgt2 data, the efficiency of S1 and S2 are still larger than 99% <br>	+
−	3) The 2nd PMT in the Ledt S1 (S1_2_L) need to be replaced <br>	+
−	4) S0 is already in the right HRS. We need to remove it <br>	+
−	5) The HV of 2 channels of the Lumi crate (Slot 15, #7 and #8) should not be turned on, <br>	+
−	otherwise they will cause the whole crate crashed;  <br>	+
−	<B>After 3) and 4) fixed, the trigger for G2P will be the same as the regular HRS trigger. </B><br>	+	Present: Ryan, Ellie, J.P., David
		+	'''Feature Presentations :
−	*Chao, Min, Pengjia:	+	None
−	1) Reported from UVA that the target have been cooled down and with 5T field on Tuesday, they are trying<br>	+
−	for 2.5T field today. <br>	+
−	*Karl:	+	Verbal Updates:
−	1) Bodgan told that S1m will not be ready for G2p; <br>	+
−	2) Will organize rad.con.2 training and electrical lead training <br>	+
−	3) As discussed with Jixie we need to place hall probe in the tunnel of both septa,  encourage students <br>	+
−	to help Jixie in measuring "B vs I" curve for septum coils; <br>	+
−	*Jixie:	+	*Ryan
−	1)  Show the detection efficiency of the 3rd arm. It is about 85%.	+	Working on the PRL for the ChiPT paper, just started.
−	Check [http://hallaweb.jlab.org/experiment/g2p/collaborators/jixie/20110817_ThirdArm/InelasPrBg/ThirdArmEff_E2.257.png here] for details. <br>	+
−	The following table is the rate of the 3rd arm for current design: <br>	+
−	{|border=1	+
−	|-	+
−	!Beam(GeV)	+
−	!Mom_Range(MeV)	+
−	!Hoffset(cm)	+
−	!Voffset(cm)	+
−	!Time(hours)	+
−	|-	+
−	|1.159	+
−	|270~410	+
−	|6	+
−	|0	+
−	|9.5	+
−	|-	+
−	|1.706	+
−	|320~460	+
−	|0	+
−	| -20	+
−	|9.9	+
−	|-	+
−	|2.257	+
−	|320~460	+
−	|0	+
−	| -40	+
−	|7.1	+
−	|}	+
−	Please note that the detector efficiency is not considered yet. <br>	+
−	2) Both of the 2 target field analysis from Jie and Toby shows that the current ratio is closed to 1.15. Jixie will <br>	+	*David
−	talk to survey group for checking the position for mistakes. Jixie also suggested Jie and Toby to compare the new target<br>	+	Working on resolving systematic shift in 467 Nu point for 2.2 GeV 2.5T asymmetry between left and right HRS, showed normalized yields, J.P. and Ryan suggested a tight dp cut. Also discussed the suspiciously good chi^2 generated with the method J.P. suggested before, J.P. said he thinks it is fine that the chi^2 is small but that it is necessary to evolve the kinematics of one arm to the other one before combining the 2.5T asymmetries. Also mentioned working on a cross check for the 5T data for g2 with Toby and Ryan, but has a sign error, it was suggested for David to fix the sign of the asymmetry to the theory or the elastic asymmetry peak.
−	field map from Robin to the exist one. If we can not explain this 1.15 current ratio, we need to measure the field on the can surface again. <br>	+
−	3)Will measure the "B vs I " curve for septa when power supply ready.  We need 2 gauss meters and 2 probes to place in the septa<br>	+
−	during experiment.  Will cost about $6000. <br>	+
−		+
−	*Jie:	+
−	1) Found that the current ratio is about 1.15. Will check bug for Toby and try to improve the field analysis <br>	+
−	*Toby:
−	1) Found that the current ratio is about 1.14.  <br>
−	2) Will check bug for Jie's program and try to improve the result <br>
−	*Melissa:	+	==09/22/2017==
−	1) Checking the ADC of preshower and shower <br>	+
−	*Ryan:	+	Present: Ryan, Chao, Ellie, Karl, David
−	1) Will look into the HV problem mentioned above. <br>	+
−	2) Check the Y distribution at S1m to see if S1m will lose acceptance. This position is projected <br>	+
−	from the focus plane.  See the [http://hallaweb.jlab.org/experiment/g2p/collaborators/rbziel/YDistributions.pdf details here].<br>	+
−	Note: we will not be able to use S1m. <br>	+
−	3) Will clean the unnecessary cables for the HRS ; <br>	+
		+	'''Feature Presentations :
−	----	+	None
−	<B>8/10/2011</B>:	+
−	Present: Karl, Jixie, Chao, Pengjia, Min, Vincent, Jie <br>	+
−	By Phone: Mellisa, Ryan, Toby	+
−	*Karl:	+	Verbal Updates:
−	1) Target is not cool down yet, still filling helium. Ryan, Toby and Mellisa are already there. <br>	+
−	2) Can not find 2 cm SC <br>	+
−	3) Got approved that we will have 12 days of 1.7 GeV beam (may be a old news to someone). <br>	+
−	4) Tried to extend to run the experiment during Christmas <br>	+
−	*Jixie:	+	*Ryan
−	1) Talked to Bogdan and Albert for 2cm SC. There is no EXTRA 2 cm SC that can be used for us. <br>	+	Sent model codes to David, discussed dilution's odd behavior at nu > 1000 MeV, explained that previously he and Toby have switched to a model above 950 MeV abruptly from data. Said that packing fraction systematic error doubled after Toby fixed the radiative correction issue. Karl and Ryan discussed the issue of Toby assuming the ratio of carbon to nitrogen was a flat 15%, where Ryan was able to find a paper plotting it vs W.
−	2) Talked to Brad and Bob about 10K Hz DAQ rate with ADC. Both of them are said there need some <br>	+
−	efforts to make this happened. <br>	+
−	3) Finalized the 3rd arm design: <br>	+
−	A) Since 2cm SC is not available, we will switch back to 1 cm SC for the 1st plane;  <br>	+
−	B) The neutron shielding will be 30 cm thick and we will use the exist borated plastic; <br>	+
−	C) The width of of SC plane will be extended from 6 to 8 inches; <br>	+
−	D) We will put a removable 2mm aluminum shielding to shield low energy background from the target.<br>	+
−	We will not use this shielding for 1.2 GeV. For 1.7 and 2.3 GeV, we will use it only if the DAQ rate<br>	+
−	can not reach 10k Hz<br>	+
−	E) We changed the detected energy range for 1.7 and 2.3 GeV. <br>	+
−	4) Calculated the maximum raster size (requested by Karl). It is ok to extended to 11 mm.	+	*Chao
−	[http://www.jlab.org/~jixie/HallA/meeting/20110810_ThirdArm/RasterVsBeamAngle_D25.4mm.png raster size assuming 25.4mm target cell diameter]. <br>	+	Unable to speak, but will present 5T 2.2 GeV acceptance next week.
−	We will have the target cell diameter of 27mm, [https://hallaweb.jlab.org/dvcslog/g2p/125], which will allow to <br>	+
−	extend to 11.5 mm.	+
−	*Chao:	+	*David
−	1) Simulated the 3rd arm. There is a bug in calculating the asymmetry. Need to recalculate the time<br>	+	Has generated g2 for 2.5T 2.2GeV data, will refine over the coming week.
−	2)After fixed the bug in the code, found the final position and rates: <br>	+
−	Check details [http://www.jlab.org/~cg2ja/Chao_WeeklyMeeting_08102011.pdf here].	+
−	*Min:	+	==09/06/2017==
−	1) Solve the snake problem in linux by using -fno-automatic option. <br>	+
−	2) Wrote a [http://hallaweb.jlab.org/experiment/g2p/technotes/E08027_TN2011_03.pdf note] about the optics discussion with Jixie.	+
−	*Pengjia:	+	Present: Karl, J.P., David, Ellie
−	1) Will looking to the low current data taken during Xgt2 to check noise of adc in BCM|BPM <br>	+
−	2) Arne will test the tungsten colorimeter with heater some time next week <br>	+
−	3) The ring buffer is working, will move on to read ADC and helicity signal, and TCPIP program which <br>	+
−	will be used to communicated between the ring buffer and HRS DAQ <br>	+
−	*Jie:	+	'''Feature Presentations :
−	1) Shown improved result. After optimizing the fitting ranges, the variation of data to tosca reduce to 3%,<br>	+
−	and the position offsets are all within 1 cm.  Check [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/fieldmap3.pdf | this] for details.<br>	+
−	----	+
−	<B>8/3/2011</B>:	+
−	Present: Karl, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Jie	+
−	*Karl:	+	*David
−	1) Organized student go to UVA to participant the target cool down	+	Showed a study on the left and right arm HRS asymmetry comparison for 2.5T. Was able to replicate Ryan's results for 5T asymmetries, J.P. and Karl suggested redefining the chi^2 in terms of the uncertainty of both arms to remove ambiguity. 2.5T 2.2 GeV asymmetries show good agreement with the exception of three data points, which David is investigating, after noting that the runs going into those data points jump by about 5 days and change target material. Karl and J.P. suggested it was also important to obtain information about whether Toby's dilutions should change based on the target material. More details on his slides can be found [https://hallaweb.jlab.org/wiki/images/4/43/G2pHRSCompare.pdf here].
−	*Jixie:	+	Verbal Updates:
−	1) The detector response function is ready in the Geant4 simulation program. <br>	+
−	[http://www.jlab.org/~jixie/HallA/meeting/20110803_ThirdArm/Edep_ElasPr.png | Energies deposited by elas proton] <br>	+
−	[http://www.jlab.org/~jixie/HallA/meeting/20110803_ThirdArm/n_EdepVsPid.png | Hits in neutron simulation] <br>	+
−	[http://www.jlab.org/~jixie/HallA/meeting/20110803_ThirdArm/n_Edep_E2.257.png | Total energy deposited by neutron.]	+
−	(Please note that the top panel is still for the 2nd plane, not the 1st plane.) <br>	+
−	The energy deposited into the 2nd plane indirectly from the neutron is about 188 MeV per 100K 2.3 GeV electrons<br>	+
−	or 160 ns with 100 nA beam current. It turns out we must have the neutron shielding!	+
−	2) To shield the neutron, 20 cm thick plastic (Polyethylene) can block 80~85% of the neutron flux. <br>	+	None
−	Check detail here: [http://www.jlab.org/~jixie/HallA/meeting/20110803_FLUKA/] <br>	+
−	3) Third arm detector design: Al confirm that we can put 20 cm thick plastic shielding. <br>	+	==08/23/2017==
−	The detector will be located 70 degrees, 2.1 meter away from the target. The SC plane size is 6'X 24', <br>	+
−	with rotation by the vector (r=1, theta=70, phi=0) about 36 degrees (for 5T target field) or 18 <br>	+
−	degrees(for 2.5T target field).  The 60 degrees of rotation about Y axis is not necessary since the shielding<br>	+
−	for neutron is in place. The first layer of SC will be 2cm, and the 2nd layer will be 5 cm or 2 inches. <br>	+
−	We need to find 2cm scintillator. The center position for each beam energies are the following: <br>	+
−	1.159  Horizontal_offset = 6 cm,  Vertical offset = 0 cm OR Horizontal_offset = 0 cm,  Vertical offset = 18 cm <br>	+
−	1.706  Horizontal_offset = 0 cm,  Vertical offset = -21 cm <br>	+
−	2.257  Horizontal_offset = 0 cm,  Vertical offset = -15 cm <br>	+
−	The position can allow 1~2 cm off, and the angle can allow 2 degrees off. <br>	+
−	4) Have already inform Al with this design. <br>	+
−	*Chao:	+	Present: Ryan, J.P., Toby, David, Alexandre
−	1) Ran Geant4 simulation for the 3rd arm. Verified the rotation and position. <br>	+
−	2) Recalculate the rates. It will take about 14, 10, 7 hours to measure Pb*Pt to 5% uncertainty with 1.2, <br>	+
−	1.7 and 2.3 GeV beam. If we increase the SC wider it will shorten the time for 1.2 GeV but longer the time for<br>	+
−	the others due the the signal to background noise get worse. We still need to optimize the design. <br>	+
−	*Ryan:	+	'''Feature Presentation :
−	1) Working on trigger on S1m <br>	+
−	2) Looked in the Y distribution of S0, it is about 15 cm, it seems ok for acceptance.	+
−	[http://hallaweb.jlab.org/experiment/g2p/collaborators/rbziel/s1m_proj.pdf | Figure 1]	+
−	[http://hallaweb.jlab.org/experiment/g2p/collaborators/rbziel/s1m_proj_25.pdf | Figure 2]<br>	+
−	3) Got the timing module working after replacing the broken cables. Bob suggested to unplug HRS cable and reconnect them.<br>	+
−	4) Will work on the HOWTO wiki pages <br>	+
−	*Toby:	+	None
−	1) Checked the probe with known field in the magnetic group with Jixie, Chao and Jie. Both the 3-axis probe and <br>	+
−	the axial probe seems within 1% accuracy. But we did not check the variance of the axial probe in rotation. <br>	+
−	Plan to do this in UVA.  <br>	+
−	2) Determined the current ratio to be around 1.0. Jixie suggested to check again.	+
−	*Jie:	+	Verbal Updates:
−	1) Improved the field analysis result. He analysis the data X_table=44 or X_table=46, which is most closed to the z axis. <br>	+
−	The new current ratio is 1.151, the position offsets are Xoff~=1.2 cm, Yoff=-0.5 cm, Zoff=0.4cm. Rotation and Xoff is not <br>	+
−	sensitive at all in this data set because the field is almost flat when x is closed to 0. <br>	+
−	Check the detail here: http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/fieldmap.pdf <br>	+
−	2) Will use large X data to fit for rotation and Xoff. <br>	+
−	*Min:	+	*Ryan
−	1) Tried to pull fortran routines from cern packages. But too many to pull! Jixie suggested stop doing this. <br>	+	Discovered the the divergence in XS from Toby was because the radiation lengths were flipped in Toby's analysis-- TA comes after TB (T after and T before). Toby promised to re-run the code and ensure
−	*Pengjia:	+	*David
−	1) Successfully build the ring buffer to store BCM|BPM signal on HAPPEX DAQ <br>	+	Working on Left+Right HRS 2.5T comparison still, trying to get Chi^2 for 5T comparison to be as good as in Ryan's analysis. Using same runs, LHRS asymmetry agrees with Ryan's but RHRS differs for three data points.
−	2) Will post the target connection diagram which can help to understand the target cool down. Check Elog entry 124 <br>	+
−	for detail https://hallaweb.jlab.org/dvcslog/g2p/124 <br>	+
		+	==08/09/2017==
−	----	+	Present: Ryan, Chao, J.P., Karl, David
−	<B>7/27/2011</B>:	+
−	Present: Karl, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Jie	+
−	*Jixie:	+
−	1)Neutron flux simulation.[http://www.jlab.org/~jixie/HallA/meeting/20110727_Neutron/try1 | details]<br>	+
−	There will be about 1.3~1.5 neutrons for each 2.3 GeV electron hitting the local dump. <br>	+
−	For 6'x24' 3rd arm detector located at 70 degrees and 2.1 meters away from the target, <br>	+
−	there will be about 0.0012 neutrons per 2.3 GeV electron. If converted to rates, <br>	+
−	it will be about 800 MHz @ 100 nA beam current.  This result has been confirm by a FLUKA program ran<br>	+
−	by Lorenzo Zana (who is checking the radiation for PREX2).<br>	+
−	''Jixie will work on shielding the neutron.''	+
−	2)Working on third arm simulation. [http://www.jlab.org/~jixie/HallA/meeting/20110727_ThirdArm |details ]<br>	+
−	If rotated the 3rd arm by Y axis with 60 degrees (the the SC plane will be 10 degrees with <br>	+
−	respected to X axis), we can have 3 advantages: <br>	+
−	A)reduce the neutron flux by a factor of 5 (=sin(70deg)/sin(10deg)) <br>	+
−	B)do not need to cut the scintillator plane <br>	+
−	C)effective thickness doubled and will have better ability to cut ADC for triggers. (need to simulate ...) <br>	+
−	But it require more space in the target platform. Need to check with Al <br>	+
−	3)Can not understand how the neutron will affect the 3rd arm trigger without the detector response<br>	+	'''Feature Presentation :
−	simulation. Jixie will add detector response into the Geant4 simulation.	+
−	*Chao:	+	None
−	1) Working with Jixie on the 3rd arm simulation. Confirm the rotation angles and tried to find<br>	+
−	the best positions for each beam energies. <br>	+
−	2) Recalculated the rate for the 3rd arm.	+
−	*Jie:	+	Verbal Updates:
−	1) Tried to improve the analysis on the target field <br>	+
−	*Min:	+	*Chao
−	1) Checked the self consistency of the HRS transportation packages. <br>	+	Working on optics runs to complete acceptance study, trying to figure out a way to work around not having definitive BPM Results.
−	2) The SNAKE works only in SunOS but not. MUDIFI works on jlabl2 but not on jlabs3. It was assumed to<br>	+
−	be the cernlib problem. Karl suggested to pull the needed fortran routines out of cern packages and <br>	+
−	build a stand-alone snake program. <br>	+
−	*Mellisa:	+	*Ryan
−	1) Finished checking the [https://www.jlab.org/~melissac/cherenkov_analysis.pdf Cherencov]. <br>	+	Trying to get signatures from committee on thesis, still waiting to hear back from Toby about dilution issues.
−	2) Will move on to check the ADC signal of pre-shower and shower. <br>	+
−		+	*David
−	*Ryan:	+	Working on Left+Right HRS 2.5T comparison, have preliminary results but with a very large Chi^2 of ~25, trying to work on account for second order effects to knock that down and make sure it is viable to combine the data from both arms.
−	1) Checking timing for L1A (Level 1 acceptance)	+
−	2) Working on the trigger on S1m	+	==08/02/2017==
		+
		+	Present: Ryan, Karl, David, J.P.
		+
		+	'''Feature Presentation :
		+
		+	None
		+
		+	Verbal Updates:
		+
		+	*David
		+	Still working on HRS asymmetry comparison for the LHRS and RHRS, installing ROOT and configuring local coding environment. Ryan agreed to help guide David through setting up his environment.
		+
		+	Discussed intelligent magnet power supply, which David will investigate communicating with via USB, irrelevant to the g2p collaboration.
		+
		+	*Ryan
		+	Thesis edits essentially complete, L+R HRS Comparison had an angle difference of .3 degrees
		+	Ryan and Karl discussed trying to get a better dilution and packing fraction from Toby to deal with other issues in 2.5 T 2.2 GeV data
		+	Ryan should be able to get shell of Hyperfine results soon
		+
		+	*Karl
		+	Karl asked Xiaochao to contact Jie about finishing the BPM analysis, Jie responded that he will not finish the analysis.
		+	In terms of administrative issues, Karl agreed to add David to g2p mailing list so that he can take over sending out weekly meeting emails from Ryan.
		+
		+	==07/19/2017==
		+
		+	Present: Ryan, Toby, Karl, David
		+
		+	'''Feature Presentations :
		+
		+	*Toby
		+	Showed an update on the dilution and packing fraction calculation for 2.5T. This is an issue at large nu where the fit to the packing fraction and dilution grow large where the model expects them to level off. Toby thinks this might be an issue with the radiative scale factor he is applying to the data. There is also some questions about the choice of acceptance cut used to generate the quantities. He chose a large acceptance cut to improve statistics but this might have systematic effects causing the rise. He will repeat the analysis at a few difference acceptance cuts to check this effect.  More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/2Tdilution_071917.pdf here].
		+
		+	Verbal Updates:
		+
		+	*David
		+	Working on HRS asymmetry comparison for the LHRS and RHRS
		+
		+	==07/12/2017==
		+
		+	Present: Ryan, Toby, Karl, Ellie, David, Chao
		+
		+	'''Feature Presentations :
		+
		+	*Ryan
		+	Showed beam energy values for the experiment run period on production runs. There are some  bigger than expected fluctuations. To first order the effect of this is small (Mott XS variation) but the question is how this could effect calibrations, such as the BPM calibration. More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_071217.pdf here].
		+
		+	Verbal Updates:
		+
		+	*Toby
		+	2.5 T packing fraction values. Taking into account yield drifts gives a systematic error on the order of 15% at 2.2 GeV 2.5 T. Looking into 1.7 GeV settings next
		+
		+	*David
		+	Working on HRS asymmetry comparison for the LHRS and RHRS
		+
		+	*Chao
		+	Working on acceptance simulation. Running simulation for the production runs. Slow going because he can only runs a handful of jobs at a time.
		+
		+	==07/05/2017==
		+
		+	Present: Ryan, Karl, Toby, J.P., Chao, David
		+
		+	General Discussion:
		+
		+	*Batch farm is prioritizing multi-threaded jobs so this will impact g2p replay and also Chao's acceptance simulation timeline.
		+
		+	*Toby is going to start looking at the 2.5T dilutions this week.
		+
		+	*David has generated asymmetries but results are consistent with zero so he will try larger binning (up from 10 MeV)
		+
		+	==06/28/2017==
		+	Present: Ryan, Toby, David, Karl, Chao, JP, Alexandre, Xiaochao, Ellie
		+
		+	General Discussion:
		+	*2.5T data quality. Based upon error bars from a quick moment analysis of the 2.5T data from Ryan it appears that the 2.2/1.7 GeV data is useful for publication with Q2 values of approx 0.04 GeV2 and 0.02 GeV2, respectively. The 1.1 GeV data error bars are very large, which is in part due to the very small asymmetry prediction at that low Q2 (0.009 GeV2).
		+
		+	*Toby is leaving to start a job on July 24. He will try and get something together for the dilution and packing fraction analysis for the 2.5T settings.
		+
		+	*Chao is making good progress with the longitudinal acceptance for the carbon data. He is able to produce a continuous spectrum with good agreement in the overlap regions at large nu. Unfortunately there is no overlap around the delta-resonance. He will do a similar study except at the transverse settings next.
		+
		+	*David is going to work on the data quality check for the 2.5T asymmetries. His first step is to produce g2p asymmetries and compare to results from Ryan and Toby.
		+
		+	==06/21/2017==
		+	No meeting because of Hall A collaboration meeting.
		+
		+	==06/14/2017==
		+
		+	Present: Ryan, Karl, Toby, J.P.,Chao
		+
		+	'''Feature Presentation :
		+
		+	*Ryan
		+	Showed the results of a quick analysis of the 1.7 and 1.1 GeV 2.5 T settings. The 1.7 GeV data looks pretty good and can most likely be used going forward. There is one momentum setting just previous to the delta where the majority of the data was taken with a mismatched septa and dipole configuration, so it is not included in these slides. He will try including this data to see the effect it has on the results. It should probably be OK for the asymmetry. The 1.1 GeV data looks worse statistically, which related to the much smaller asymmetry that we see as we go to lower and lower Q2.  As we go to lower Q2 we also have the added complication of the Christy fit we're using for the unpol XS getting worse and worse. Going forward Ryan will do a quick moment analysis of this data. More details on his slides can be found  [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_061417.pdf here].
		+
		+	*Toby
		+	Showed different methods for calculating the low-x portion of the BC sum rule. These include the polarized PDF's and Hall B model. The problem is that none of these methods are really applicable at the g2p kinematics (PDF's hold down to Q2 = 1 GeV2), and that the low-x portion of the integral must be a sizable contribution for the BC sum rule to hold. Going forward we will most likely assume that the BC sum rule holds and use that assumption to place a limit on the low-x behavior of g2 at low Q2. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/bcsum_unmeasured_061417.pdf here].
		+
		+	==06/07/2017==
		+
		+	Present: Ryan, Karl, Toby, J.P.,Chao, Ellie
		+
		+	'''Feature Presentation :
		+
		+	*Ryan
		+	Showed the results of a quick analysis of the 2.2 GeV 2.5 T settings. The goal of this analysis was to check the overall quality of the data  and includes the combined statistics of both the RHRS and LHRS. The overall statistical precision of the data is pretty good considering the much lower target polarization of the 2.5T settings (15% on average compared to the 70% for the 5T runs). Going forward he will do a similar study for the 1.1 GeV and 1.7 GeV settings and also complete a very preliminary moment analysis of these settings. These settings also need a completed dilution and packing fraction analysis  [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_060717.pdf slides].
		+
		+	Verbal Updates:
		+	*Jie
		+	Published his BPM tech-note update to the wiki.
		+
		+	*Chao
		+	Summarized his acceptance study progress. So far he has applied his 8mm raster cut method (+/- 15mrad in ph and 20 mrad in th) to the elastic carbon long. setting and gets 5% agreement between the simulation and data. He is able to drastically reduce the uncertainty in the raster cut by cutting on current and not size. The timing information of the raster is known very well. He knowns the time the raster spends inside the area of the cut and the time it spends outside. The ratio between these two times is scaled to the total charge. He is currently applying this to all the carbon dilution data at longitudinal to see how this procedure works at other P0. He estimates this will take 2-3 weeks. After that he will move onto the transverse setting and estimates that will take an additional 1-2 months to complete.
		+
		+	==05/31/2017==
		+
		+	Present: Ryan, Karl, Toby, J.P.,Chao
		+
		+	'''Feature Presentation :
		+
		+	*Toby
		+	Showed an update on his g2 moment calculations. His moments included the BC sum rule and also DeltaLT. From his analysis it was concluded that it is very difficult to verify the BC sum rule at low Q2 because of the lack of data at low x. The DeltaLT results look much better. More details on his slides are found [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/g2moments_talk_053117.pdf here].
		+
		+	Verbal Updates:
		+	*Jie
		+	Still working on his BPM tech-note/update.
		+
		+	*Chao
		+	Planning on talking with JP about his acceptance study update. Had to leave early to go to another meeting.
		+
		+	==05/24/2017==
		+
		+	Present: Ryan, David, Karl, Toby, J.P., Jie, Ellie
		+
		+	'''Feature Presentation :
		+
		+	None
		+
		+	Verbal Updates:
		+
		+	*Jie
		+	Still working on his BPM tech-note/update. Hopes to have it done by next week. This might also be his last g2p meeting before he starts his new job. Will also add his thesis to the wiki.
		+
		+	==05/17/2017==
		+
		+	Present: Ryan, David, Karl, Toby, J.P. Chao
		+
		+	'''Feature Presentation :
		+
		+	*Ryan
		+	Showed an analysis for an explanation for why the 2.2 GeV Longitudinal polarized DS does not go to zero below the pion production threshold after tail subtraction. His idea is that the elastic radiative events come from a different part of the acceptance than the inelastic events. This effect could be potentially large if a large acceptance cut is used. The big unknown in this analysis is what is the exact angle difference. With the current reconstruction/simulation status it's very difficult to determine. In the future, if the simulation is able to reproduce the angular acceptance then the tails can be calculated and weighted for the simulated acceptance. This also raises potential problems for getting a polarized DS from an asymmetry and cross section calculated with different acceptance cuts. For now, the analysis will proceed with the old method and assume one scattering angle. Ryan will check the results of using a tight asymmetry and tight cross section cut to see how the tail subtraction is effected. More details on his slides are found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_051717.pdf here].
		+
		+	*Chao
		+	Showed an update on the optics simulation and he is currently trying to beat down the systematic error from making a raster cut. He is currently cutting on raster current as opposed to raster size to improve the uncertainty. With a raster cut the simulation is much better able to reproduce the data.
		+
		+	==05/10/2017==
		+
		+	Present: Ryan, Jie, David, Toby, Ellie, JP
		+
		+	'''Feature Presentation :'''
		+
		+	*Ryan
		+	Showed an analysis update of the results section of his thesis and includes analysis of all of the 5T settings. He evaluated the g1 moments and the hyperfine splitting contributions for g1 and g2.  More details on his slides are found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_051017.pdf here].
		+
		+	==05/03/2017==
		+
		+	Present: Ryan, Jie, David, Karl, Toby, Ellie, JP, Chao
		+
		+	'''Feature Presentation :'''
		+
		+	*David
		+	Showed an update for calculating the acceptance correction by normalizing to the elastic cross section. His uncertainty in this method is slightly better than the results Toby showed before and his dominant uncertainty is the scattering angle reconstruction and it's effect on the Mott XS and elastic form factors. He will look into further separating the quasi-elastic and elastic peaks by subtracting out the elastic tail for helium-4. More details on his slides are found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/xsscalefactor.pdf here].
		+
		+	==4/26/2017==
		+
		+	Present: Ryan, Jie, David, Karl, Toby, Ellie
		+
		+	'''Feature Presentation :'''
		+
		+	*Ryan
		+
		+	Showed results of a parallel asymmetry analysis between Toby and Ryan. The asymmetries agree very well and the only slight difference is at the longitudinal setting. This difference is a result of slightly different acceptance cuts used in the analysis and goes away if the same cuts are used.  More details on his slides are found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_042617.pdf here].
		+
		+	*Toby
		+	Posted an update on last weeks slides to include a model comparison to his calculated cross sections. His slides are found [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/xs_talk_042617.pdf here].
		+
		+	==4/19/2017==
		+
		+	Present: Ryan, Jie, David, Karl, Toby, Ellie, Chao<br>
		+
		+	'''Feature Presentations :'''
		+
		+	*Toby
		+
		+	Showed a comparison between calculating polarized cross sections using a model and using data. In the data method he multiplies the raw asymmetry by the raw cross section with no dilution correction. In the model method he applies the dilution to the asymmetry and then uses a unpolarized proton model (radiated). The two results agree pretty well except for the 3.3 GeV setting where the yield drifts present problems with the dilution and cross section calculation. We will most likely have to use a model at this setting. More details on his slides are found [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/xsdiff_041917.pdf here].
		+
		+	Verbal Updates:
		+
		+	*Chao
		+
		+	Talked about using the raster cut in the simulation to match data and simulation for the acceptance. He's going to soon try and apply this raster cut method across the momentum settings at the longitudinal setting and see how well the simulation can match data. He's currently using a 30 mRad phi cut, which is significantly larger than the cut Toby is using and will the systematic uncertainty from knowing the cut boundary. There is going to be an additional systematic from using a raster cut when it comes to calculating the accumulated charge. He is looking into this.
		+
		+	==4/12/2017==
		+
		+	Present: Ryan, Jie, David, Karl, Toby, JP, Ellie<br>
		+
		+	No presentations this week. Toby and Ryan are working on comparing their asymmetry results to confirm that their methods agree. Jie's graduation date is May 9 and he is still working on finishing up his thesis.
		+
		+	==3/29/2017==
		+
		+	Present: Ryan, Jie, David, Karl, Toby, JP, Chao, Ellie<br>
		+
		+	'''Feature Presentations :'''
		+
		+	*Ryan
		+	Showed an update including the Gamma1 and GDH moment calculations. The results have very good statistical error bars when compared with the Hall B data and also his integration of the Hall B data agrees with the published Hall B results. More details can be found in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_032917.pdf here].
		+
		+	*Chao
		+	Showed an update on the simulation for Run 5612. He is able to reproduce the edges of the acceptance better if he places a very tight cut on the raster size. This suggests a beam position reconstruction issue. Going forward he is going to look at the uncertainty introduced by this raster cut and see which has the larger contribution to the uncertainty: raster cut or acceptance cut. More details can be found in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/chao/weekly/Chao_WeeklyMeeting_20170329.pdf here].
		+
		+	==3/22/2017==
		+
		+	Present: Ryan, Jie, David, Karl, Toby, JP, Chao<br>
		+
		+	'''Feature Presentations :'''
		+
		+	*Ryan
		+	Showed a comparison between the Bosted model and low Q2 SLAC data. The agreement between data and the model is better at larger Q2 and around 15% at the 5T setting kinematics. Ryan is waiting on an updated model from Eric Christy that includes the low Q2 data in the fit. More details can be found in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_032217.pdf here].
		+
		+	*Toby
		+	Also showed a comparison between the Bosted model and the SLAC data but included a preliminary g2p cross section as well. The agreement is at the 15% level with our data. More details can be found in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/xs_talk_032217.pdf here].
		+
		+	*David
		+	Showed a method for calculating the helium-4 elastic cross section from g2p empty dilution runs. He compares the g2p data to the Rosenbluth result from the MSW (McCarthy-Sick-Whitney) form factors and get's agreement at the 10% level. He will look into adding systematic uncertainty estimates to both his measured and calculated quantities. He will also investigate the 'Delta E' term in the elastic peak radiative corrections. More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/he4crosssectionanalysis3.pdf here].
		+
		+	Verbal Updates:
		+
		+	A request was made by Eva-Maria Kabuss for some g2p slides to present at DIS 2017 (April 3-7).
		+
		+	==3/15/2017==
		+
		+	Present: Ryan, Jie, David, Karl, Toby, JP, Chao, Ellie<br>
		+
		+	'''Feature Presentations :'''
		+
		+	*Chao
		+	Showed an update on the optics and acceptance simulation. He showed that for a carbon run with no liquid helium and at the longitudinal target configuration he is able to match data to simulation with a very tight acceptance cut. He is working on expanding this cut to reduce the overall systematic uncertainty in the acceptance. Super elastic events and carbon excited states make expanding this range difficult. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/chao/weekly/Chao_WeeklyMeeting_20170315.pdf here].
		+
		+	Verbal Updates:
		+	*Jie
		+	Graduation date is set for May 9, 2017.
		+
		+	==3/8/2017==
		+
		+	Present: Ryan, Jie, David, Karl, Toby, JP<br>
		+
		+	'''Feature Presentations :'''
		+
		+	*Ryan
		+	Showed an update on how he is extracting g1 from the longitudinal data and evolving it to a constant Q2. He also showed a preliminary calculation of the gamma0 moment, which agrees well with the current Hall B measurements and chiral perturbation theory predictions. More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_030817.pdf here].
		+
		+	==3/1/2017==
		+
		+	Present: Ryan, Toby, David, Jie, JP, Karl, Ellie, Chao<br>
		+
		+	'''Feature Presentations :'''
		+
		+	*Ryan
		+	Showed an update on the systematic error analysis going into the asymmetries, polarized cross sections and radiative corrections. Currently the dominating systematic error is from the angle reconstruction and use of an unpolarized model to create the polarized cross sections. The angle reconstruction error is amplified at low angles because of the strong Mott dependence. The unpolarized cross section systematic could be reduced in the future by substituting in g2p data for that component. More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_022917.pdf here].
		+
		+	*Jie
		+	Gave an update on the BPM calibration process. Showed that there is a strong position dependence to the off-sets determined from Harp scans. Through the reconstruction procedure he is unable to reproduce the location of the harp scan points because of this position dependence. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2017_0301_plots/yields_update_20170301.pdf here].
		+
		+	*Toby
		+	Presented the status of the dilution analysis for the 3.3GeV settings. The analysis is complicated by the large yield drifts seen in the data. He is still trying to figure out a method to give reasonable dilution results at this setting. But whatever method he settles on will most likely come with an increased level of systematic error. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/3350_dilution_talk.pdf here].
		+
		+	==2/22/2017==
		+
		+	Present: Ryan, Toby, David, Jie, JP<br>
		+
		+	'''Feature Presentations :'''
		+
		+	No feature presentations this week. Everyone is planning on presenting next week.
		+
		+	==2/15/2017==
		+
		+	Present: Ryan, Toby, David, Jie, JP<br>
		+
		+	'''Feature Presentations :'''
		+
		+	*Jie:
		+	Showed an update the BPM calibration. There was some discussion on the base assumptions Jie is making in removing potential position dependence on some calibrations constants (b-/b+). More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2017_0214_plots/yields_update_20170215.pdf here].
		+
		+	'''General Discussion :'''
	*Toby:		*Toby:
−	1) Optimized the fitting range in the field analysis	+	Updated target polarizations are available now.
		+	*Ryan:
		+	HERMES publication from 2013 of new BC Sum Rule calculation at Q2 = 5 GeV2. Data is consistent with 0 but with large error bars.
−	----	+	==2/8/2017==
−	<B>7/20/2011</B>:	+
−	Present:Karl, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Alexandre, Jie Liu	+
−	*Jixie:	+	Present: Ryan, Toby, David Karl, Jie, JP, Chao, Ellie<br>
−	1) The design of the 3rd arm:  <br>	+
−	A) We need to place the 3rd arm at 70 degrees, not 72. We also have to move the detector <br>	+
−	from 1.5 meter to 2.1 meter such that the local dump itself could block some background.<br>	+
−	B) [http://www.jlab.org/~jixie/HallA/meeting/20110720_ThirdArm/ThetaAcc_R1B2G5.png | Figure 1 ]	+
−	shows the hit positions on the SC plane. The distribution look like a rotated strip. <br>	+
−	In order to select a small range of theta, the SC need to be rotated to some angle. <br>	+
−	C) [http://www.jlab.org/~jixie/HallA/meeting/20110720_ThirdArm/ThetaAcc_N17.png | Figure 2 ]	+
−	and [http://www.jlab.org/~jixie/HallA/meeting/20110720_ThirdArm/ThetaAcc_removed.png | Figure 3]	+
−	show the hit position for protons within and out of the theta range. <br>	+
−	Please note that these protons are generated in a flat distribution of theta and Energy. <br>	+
−	they are not elastic proton. Jixie will run with elastic proton again to check the rotation. <br>	+
−	D) We might need to cut the SC from 12 inches width to 6 inches. <br>	+
−	E) JP mentioned that it might help if the SC plane be rotated about Y axis by 70 degrees. <br>	+
−	With this rotation the whole SC will have minimum cross section area facing the local dump. <br>	+
−	2) Still working on neutron flux simulation.	+
−	*Chao:	+	'''Feature Presentations :'''
−	1) Simulate the 3rd arm detector located at various distance from the target (1.5, 1.75,2.0, 2.25 meter).<br>	+
−	The detector size in the simulation is 6' x 24'. According to his result the dilution factor is about 17% <br>	+
−	and the total time to accumulate 5% accuracy data is about 9 hours. <br>	+
−	*Min:	+	*Ryan:
−	1) Check the no target field HRS transportation code	+	Showed the final systematics for the inelastic and elastic RC's. The end result is 2-3% for the elastic tail and 3-5% for the inelastic RCs. More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_020817.pdf here].
−	*Pengjia:	+	'''General Discussion :'''
−	1) learning the HAPPEX DAQ	+
	*Toby:		*Toby:
−	1) Show field analysis result on the can surface data set. After improve, the variation of measured field<br>	+	Updating his systematic uncertainty on the target polarization analysis.
−	to the map are within 1%. But the position offsets are still in 2 cm level. This analysis used only point A <br>	+
−	position to calibrate all the data set, which leaves room for further improve. Jixie ask Toby to check <br>	+
−	the code carefully. <br>	+
−	*Jie:	+	==2/1/2017==
−	1) Show field map analysis. His result does not agree with Toby's.	+
−	*Ryan:	+	Present: Ryan, Toby, David Karl, Jie, JP, Chao, Ellie<br>
−	1) Working on mapping the HRS HV.  Finish ROC3 and ROC4. Check Elog entry 122 for detail: <br>	+
−	https://hallaweb.jlab.org/dvcslog/g2p/121 <br>	+
−	2) Will work on DAQ with Alex <br>	+
−	3) Will check PMT signal for S1 and S2m <br>	+
−	*Mellisa:	+	'''Feature Presentations :'''
−	1) Working of the safety documents which is drawn from SANE group. <br>	+
−	2) Checking the Cherencov, found the ADC for 1 photon-electron, but this result still need to be improved.<br>	+
−	----	+	*Jie:
−	<B>7/13/2011</B>:	+	Gave an update on the BPM analysis. Still have trouble solving the position jumps. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/20170201/yields_update_20170201.pdf here].
−	Present:Jian-ping, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Alexandre, Jie Liu, Karl	+
		+	*Ryan:
		+	Showed the outline of the g2p radiative corrections procedure, including the polarized elastic tail and RADCOR and POLRAD formulations of the inelastic RCs. Also presented systematics for the unfolding procedure. He will next finalize the theory systematics for the RCs. More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_012517.pdf here].
		+
		+	*Chao:
		+	Gave an update on the acceptance study. He showed that at the longitudinal setting the shift from 0 in the theta_tg histogram is caused by the target field. The effect is more pronounced at transverse settings. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/chao/weekly/Chao_WeeklyMeeting_20170201.pdf here].
−	*Mellisa:	+	'''General Discussion :'''
−	1) Continue checking the Cherencov detector. Applied geometry cut to the ADC. She need to find out <br>	+
−	the ADC value that 1 PHE corresponding to. Check her plots in the Elog, Item 120: <br>	+
−	https://hallaweb.jlab.org/dvcslog/g2p/120 <br>	+
	*Toby:		*Toby:
−	1) Showed the preliminary result for the field map analysis with the can surface data set. Most data <br>	+	g2p dilutions are now available on the [https://hallaweb.jlab.org/wiki/index.php/G2p_dilutions wiki].
−	points are within 6% variation. But the position offsets are as large as 2 cm.	+
		+	==1/18/2017==
		+
		+	Present: Ryan, Toby, Karl, Jie, JP, Chao, Ellie<br>
		+
		+	'''Feature Presentations :'''
	*Jie:		*Jie:
−	1) Showed his result of the field map analysis. Most data points are with 10% variation to the <br>	+	Hoping for a May graduation with his thesis split between three topics (g2p is one). Point was made that Jie must finish his BPM study before graduation because at this point he is the only one that can do it. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2017_0118_graduation_plan.pdf here].
−	TOSCA map. Jie's result does not agree with Toby's in position and current ratio. Both of them are <br>	+
−	requested to check their results more carefully.	+
−	*Pengjia:	+	*Toby:
−	1) Tried to build ring buffer in HAPPEX DAQ. Will do the tungsten calorimeter calibration in August.	+	Hoping for a May graduation with a close-to-final g2 his goal for his thesis. Finishing up the dilution analysis for 3.3 GeV 5T. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/timeline_update_011817.pdf here].
−	*Ryan:	+	*Ryan:
−	1)Looked into the HV for HRS <br>	+	Hoping for a June-August graduation with a close-to-final g2/hyperfine point his goal for his thesis. Finishing up the g2p radiative corrections procedure setup. More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_011817.pdf here].
−	2)Finish the splitter box. Check Elog entry 121 for detail: https://hallaweb.jlab.org/dvcslog/g2p/121	+
	*Chao:		*Chao:
−	1) Tried to learn and run the Geant4 simulation for the 3rd arm.	+	Gave an update on the acceptance study. He is still having a hard time matching the simulation to data. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/chao/weekly/Chao_WeeklyMeeting_20170118.pdf here].
−	*Jixie:	+	'''General Discussion :'''
−	1) Looking into the neutron background data provided by Pavel.	+
−	2) Designing the 3rd arm.	+
−		+
−	----	+
−	<B>7/6/2011</B>:	+
−	Present: Jian-ping, Kalyan, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Alexandre, Jie Liu	+
−	*JP:	+	*Karl:
−	1) Discussed the run plan with QWEAK group, ask for 12 days for 1.7 GeV. Not be granted yet. <br>	+	is looking into the EG1b data for our highest Q2 settings as the parallel component for g2.
−	Currently Hall C allow only 5 days, or If they are down then we can take the time for 1.7 GeV. <br>	+
−	The plan is still under discussion. <br>	+
−	2) If Hall B is not available, we need to be able to run 1.2 GeV. We should be very flexible and	+
−	ready for changes. <br>	+
−	3) Karl has the readiness review available. Everyone is encouraged to read and comment. <br>	+
−	4) JP will leave from 7/22 to 8/17. Kaylan will leave to India from 7/8 to 7/29. <br>	+
−	Alex will on vacation from 7/23 to 8/11. Karl will be on site from 7/11.	+
−	*Min:	+	==1/11/2017==
−	1) Just back from the summer school. Will continue working on the HRS package issues.	+
−	*Chao:	+	Present: Ryan, Toby, Karl, Jie, David, Chao<br>
−	1) Taking the detector geometry into account, recalculated the background of the 3rd arm using the epc code.<br>	+
−	2) Discuss the 3rd arm design: 12 inch width will accept +/-4 degrees in theta. With such a wide <br>	+
−	range it will take about 16 hours to measure Pb*Pt to 5% accuracy. It is too long ...  <br>	+
−	3) Finish the target field measurement with Jixie and Toby. <br>	+
−	*Pengjia:	+	'''Feature Presentations :'''
−	1)Leaning HAPPEX DAQ, will use it for BCM and BPM <br>	+
−	2)will do calorimeter test. The tungsten calorimeter will eventually used to calibrate BCM. <br>	+
−	3)Learning how the Harp work and how to use it to calibrating BPM. <br>	+
−	*Toby:
−	1) Finish Target filed mapping with Jixie and Chao. <br>
−	2) Working on analyzing the field mapping data. <br>
−
	*Ryan:		*Ryan:
−	1) Working on Left HRS trigger <br>	+	Showed the effect a 0.3 degree scattering angle difference between HRSs would have on the data. Calculated this difference using models and then compared the data to it. The data is consistent with a straight line fit at 0, so the statistics of g2p are not sufficient to make a definitive statement. Also showed a calculation for the uncertainty in the out-of-plane polarization angle using a psuedo Monte-Carlo method. The uncertainty is around 1%. Details of his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_011117.pdf here].
−	2) Will check the material of the target with Josh <br>	+
−	*Mellisa:	+	==1/04/2017==
−	1) Checking the Cherencov detector in HRS. Tried to find how many photon-electron (PHE) each PMT has <br>	+
−	in the Xgt2 data set. She need to apply the geometry cut and try again.	+	Present: Ryan, Toby, Karl JP, Jie,<br>
		+
		+	'''Feature Presentations :'''
		+
		+	*Ryan:
		+	Showed an update on the comparison between the LHRS and RHRS asymmetries for 2.2GeV 5T transverse. Using course 70 MeV bins and cutting out runs with large livetime and charge asymmetry he was able to get good agreement between the two spectrometers. The agreement is independent of the out-of-plane polarization angle correction. There is some question about the effect of the minor difference in the scattering angle between HRS's and the asymmetry. He will present on this difference at the next meeting. More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_010417.pdf here].
	*Jie:		*Jie:
−	1) Analyzing the filed measurement data.	+	Still looking into the BPM calibrations and the source of the BPM position jumps that don't see a corresponding yield change. He hopes to have this analysis wrapped up by the end of January. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2017_0103_plots/yields_update_20170104.pdf here].
−	*Jixie:	+	*Other news:
−	1) Just Finished the field measurement with help from Chao and Toby. Pengjia and Jie also provide appreciable help.<br>	+	At the 1/18/2017 weekly meeting we're planning on having a discussion on the analysis path forward. The primary focus on this discussion will be the experimental cross sections.
−	2) Measured the field in 2 ways. One is measuring the field on the can surface with an axial probe (borrowed <br>	+
−	from Josh) fixed in a aluminum block. <br>	+
−	http://www.jlab.org/~jixie/HallA/meeting/FieldMeasurement/IMG_0804.JPG <br>	+
−	Another is measuring the filed with a 3-axis probe on the translation table. <br>	+
−	http://www.jlab.org/~jixie/HallA/meeting/FieldMeasurement/IMG_0800.JPG <br>	+
−	The survey group came to the target lab and survey some positions. Just got the survey data yesterday. <br>	+
−	Jie and Toby are working on analyzing the field map measurement. Jie is focus on translation table data set <br>	+
−	and Toby is working of the can surface data. <br>	+
−	3) Talk to Pavel in the Rad. Con. group for the neutron background simulation. Pavel will provide <br>	+
−	the neutron distribution and model information such that Jixie will be able to work on radiation calculation. <br>	+
−	----	+	==12/21/2016==
−	<B>6/22/2011</B>:	+
−	Present: Kalyan, Jixie, Chao, Pengjia, Mellisa, Vincent, Ryan, Toby, Alexandre, Jie Liu	+	Present: Ryan, Toby, Karl, Vince, JP, Jie, Chao<br>
		+
		+	'''Feature Presentations :'''
	*Toby:		*Toby:
−	1) Tested 4 cables for the slow raster with Ryan <br>	+	Showed an update on the packing fraction analysis with a new method that is similar to his dilution calculation. This method gives a lower uncertainty than his elastic fit method. His two methods agree within the uncertainties for almost all of the settings. He will check the few kinematic settings where this isn't true and also try to pin down the systematic error from using the Bosted model to scale C12 to N14. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/pf_talk_122016.pdf here].
−	2) Worked with Chao and Jixie to prepare to measure the target field	+
−	*Ryan:	+	*Other news:
−	1) Continue working on the HRS trigger	+	Vince's last day at g2p meetings. Good luck at your new job Vince!
		+
		+	==12/14/2016==
		+
		+	Present: Ryan, Toby, Karl, Vince, JP, Jie, Chao<br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Jie:
		+	Showed a status update on the BPM calibration procedure. More details can be found in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_11_10_plots/yields_update_20161214.pdf here].
−	*Melissa:
−	1) Replaying xgt2 data. Looking at the pedestal of adc to find out if there are dead channels <br>
−	2) Updating the safety document for g2p based on the one used in SANE experiment
−
	*Chao:		*Chao:
−	1) Preparing a computer in the hall for the DAQ of the 3rd arm	+	Still having trouble matching the width of the simulation peaks to peaks from data. Even getting rid of all apertures did not sufficiently widen the simulation peak. He is continuing to look into it. More details can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_11_10_plots/yields_update_20161214.pdf here].
−	2) Preparing for the target field measurement	+
		+	==12/07/2016==
		+
		+	Present: Ryan, Toby, Karl, Vince, JP, Jie, Alexandre<br>
		+
		+	Verbal Updates:
		+
		+	*Toby
		+	Working on getting his dilution code back up and running
		+
		+	*Ryan
		+	Working on asymmetry comparisons between the LHRS/RHRS at 2.2 GeV 5T Transverse.
		+
		+	*Jie
		+	Talking with Pengjia still about the BPM calculation procedure. Will give an in-depth update on the status of the BPM analysis at the next meeting.
		+
		+	==11/30/2016==
		+
		+	Present: Ryan, Toby, Karl, Ellie, JP, Jie, Kalyan, Alexandre, Vince, Jixie, Chao <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Ryan
		+	Showed an update on the out-of-plane polarization angle calculation. The calculation agrees with Chao's result but still seems too large (40 - 65 degrees). Chao is working on confirming the results. Details of his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_113016.pdf here].
		+
		+	*Toby
		+	Showed an update on the packing fraction analysis. He presented final values for all settings except for 1.1 GeV 2.5 T. The difficulty at this setting is that the quasi-elastic peak is barely separable from the elastic peak so he is unsure of how to fit it. This is also a problem at the other 2.5 T settings and is manifest in the larger systematic uncertainties. Details of his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/pf_talk_113016.pdf here].
		+
		+	Verbal Updates:
		+
		+	*Chao
		+	working on out-of-plane polarization angle calculation and will also confirm the proton elastic simulation results for Toby.
		+
		+	*Jie
		+	Talking with Pengjia still about the BPM calculation procedure.
		+
		+	==11/23/2016==
		+
		+	Present: Ryan, Karl, JP, Jie, Kalyan, Alexandre <br>
		+
		+	*Jie
		+	Discussed BPM calibration method
		+
		+	*Ryan
		+	Working on calculating the out-of-plane polarization angle, with help from Chao. Hoping to confirm method with Chao and present something soon.
		+
		+	==11/16/2016==
		+
		+	Present: Ryan, Toby, Karl,Chao, Jie, Vince, Alexandre <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Jie
		+	Showed an update on the BPM calibration procedure. His correlation method for calculating the pedestals improves the uncertainty but does not affect the position reconstruction. In the calibration procedure there is an offset term that as large variations between calibration points. Pengjia fit this constant for current dependence but it is also possible it might have some positional dependence. Jie is going to talk with Pengjia about this. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_11_10_plots/yields_update_20161116.pdf here].
		+
		+	Verbal Updates:
		+
		+	*Toby is working on finalizing the uncertainties for the packing fraction analysis and is running into some issues with g2psim.
		+
		+	*Ryan is working on calculating the out-of-plane polarization angle, with help from Chao.
		+
		+	==11/02/2016==
		+
		+	Present: Ryan, Toby, Karl, JP, Vince, Alexandre <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Ryan
		+	Showed a brief update on calculating the out-of-plane angle correction to the perpendicular polarized cross sections. He will talk to Chao about how to make this calculation using the reconstructed variables in the replayed ROOT files.  More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_110116.pdf here].
		+
		+	*Toby
		+	Showed a slide on the yield spectra for the elastic runs in PF analysis at all kinematic settings. The nitrogen and helium peaks are only clearly visible at the 2.2 GeV 5T transverse setting, so he will need to adjust his fitting routine to account for this at the other settings.  More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/elastic_allsettings.pdf here].
		+
		+	==10/26/2016==
		+
		+	Present: Ryan, Toby, Karl, Jie, JP, Chao, Ellie, Vince, Jixie <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Ryan
		+	Showed an update on the polarized radiative corrections using POLRAD at the g2p kinematics (non-constant scattering angle). He showed that using the same angle fit for all the input spectra (as opposed to individual fits representing measured data) the systematic error was similar to that of data taken at a constant scattering angle. For this study he used the MAID 2007 model. He recommends using models for the RC'ing of g2p data but those models could be tuned and checked using measured data. More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_102616.pdf here].
		+
		+	Verbal Updates:
		+
		+	*Chao
		+	Working on the optics and acceptance simulation and tuning the simulation aperatures. Showed a short slide with better agreement between data and simulation. Still working on improving this.
		+
		+	*Jie
		+	Working on the BPM position calibration procedure.
		+
		+	==10/19/2016==
		+
		+	Present: Ryan, Toby, Karl, Jie, JP, Chao, Ellie, Vince, Jixie <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Toby
		+	Showed an update on his method for calculating the packing fraction, along with his estimate for the systematic uncertainty. He's hoping to finalize the results for the 5.0 T settings within the next few weeks.  More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/pf_talk_101816.pdf here]. There was some discussion that his uncertainty of ~8% in the fitting method is overestimated as described in the slides, so hopefully the systematic uncertainty is at the 10% level, maximum.
		+
		+	Verbal Updates:
		+
		+	*Chao
		+	Working on the optics and acceptance simulation and tuning the simulation aperatures.
		+
		+	*Jie
		+	Working on the BPM position calibration procedure. Still trying to fully understand Pengjia's method.
		+
		+	*Ryan
		+	Working on setting up inelastic radiative corrections procedure for changing angle of g2p.
		+
		+	==10/12/2016==
		+
		+	Present: Ryan, Toby, Karl, Jie, JP, Chao <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Jie
		+	Showed final results for the BPM pedestal uncertainty using his new correlation method for the 2.2 GeV 5T transverse setting. The uncertainties are about a factor of 3-4 better than previous and are approx. 1mm and 1mrad at the target. He is moving on to finishing this study at other settings and also looking into the BPM calibration procedure and beam position jumps.  More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_10_10_plots/yields_update_20161010.pdf here].
		+
		+	Verbal Updates:
		+
		+	*Chao
		+	Working on the optics and acceptance simulation. Believes that the previous mismatch he showed with data and simulation at bigger angular acceptance was due to the simulation aperatures blocking more events than seen in the data. Current size estimates of the aperatures is from a combination of g2p survey and historical Hall A information.
		+
		+	*Toby
		+	Working on packing fraction results and updating the systematic error analysis. Hoping to finalize shortly.
		+
		+	*Ryan
		+	Working on setting up inelastic radiative corrections procedure for changing angle of g2p.
		+
		+	==10/05/2016==
		+
		+	Present: Ryan, Toby, Karl, Ellie, Jie, JP, Jixie <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Ryan
		+	Showed the reconstructed angle for a loose cut on all of the LHRS g2p production data. The fit is a combination of a linear and exponential fit; this form is suggested from a Jixie ELOG post. For the most part there is good agreement with the data to the fit, and outliers from the fit is a potential criteria for selection of good runs. He used these fits to mimic g2p data and test RC procedures on data at different angles. He found that he could do RC's with small systematic error if he used the same fit for all input spectra. This is not the case for g2p data, so he's working on improving the method.  More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_100516.pdf here].
		+
		+	Verbal Updates:
		+
		+	*Jie
		+	Working on the BPM pedestal issue. He's now considering correlations between all channels in the BPM pedestals. This slightly increases his uncertainty but it is still smaller than Pengjia's result and helps alleviate the triple peak issue.
		+
		+	*Toby
		+	Working on packing fraction results and updating the simulation calculations needed for the cross section ratio input.
		+
		+	*SPIN 2016
		+	Chi-PT calculations of the polarizabilities are still bad. NEED DATA!
		+
		+	==9/21/2016==
		+
		+	Present: Ryan, Toby, Karl, Chao, Jie, JP, Jixie, Kalyan, Vince <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Jie
		+	Showed an update on the BPM pedestal calculation. Found a correlation between the pedestals on BPM channels. By using a rotated coordinate system, he can decouple the correlation. This allows for a reduced uncertainty in the BPM pedestal uncertainty contribution to the BPM calculation. More details on his slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_09_21_plots/yields_update_20160921_new.pdf here]. Will work on finalizing the updating uncertainty calculations and continue with checking the BPM calibration.
		+
		+	*Ryan
		+	Showed the reconstructed angles for three different asymmetry cuts for both the transverse longitudinal asymmetries. There is a difference between the hot-spot angle in the transverse asymmetry. The RHRS accepts smaller angles in the transverse configuration but this cannot account for the difference in the HRS asymmetries between L/R. More details on his slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_092116.pdf here]. He will try different cuts on different variables to try and find a set that gives agreement between the LHRS/RHRS.
		+
		+	**NO MEETING NEXT WEEK BECAUSE OF SPIN 2016
		+
		+	==9/14/2016==
		+
		+	Present: Ryan, Toby, Ellie, Karl, David, Chao, Jie, JP, Jixie, Kalyan, Vince <br>
		+
		+	'''Feature Presentations'''
		+
		+	*David
		+	Showed a statistical analysis between the LHRS and RHRS asymmetries for the 2.2GeV 5T transverse/longitudinal data. Concluded that for long. data the two spectrometers are statistically measuring the same thing. Further work still needs to be done on for the transverse asymmetries. His slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/chi2slides_2.pdf here].
		+
		+	*Toby
		+	Showed an updated packing fraction calculation where he replaces fits to the quasi-elastic and quasi-elastic contamination with the Bosted model. His packing fractions are in much better agreement with this method and the consensus is that the fit method was driving the large differences previously seen. He was given suggestions on trying to better quantify the quasi-elastic contamination, including using other models and separating the kinematic regions using acceptance cuts. More details can be found in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/pf_update_091416.pdf here].
		+
		+	*Jie
		+	While on the schedule, he will present next week.
		+
		+	==9/7/2016==
		+
		+	Present: Ryan, Toby, Ellie, Karl,  Chao, Jie, JP <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Chao
		+	Gave an update on the acceptance study of the 5T longitudinal setting. He's currently working on tuning the resolution of the simulation package. He finds that he can match the width of the elastic peak for a small range in theta and phi target but as he increases that range his simulation produces too narrow of a spectra. He is working on fixing this issue. His slides can be found [http://hallaweb.jlab.org/experiment/g2p/collaborators/chao/20160907/Chao_WeeklyMeeting_09072016.pdf here].
		+
		+	*Ryan
		+	Showed a comparison between the 5T longitudinal asymmetries using different acceptance cuts. He demonstrated that within our statistical error bars we do not need to make a bin-centering correction to the asymmetries for the longitudinal setting. He also tried to see if a model accurately described the asymmetry change with angle but was not successful. More details can be found in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_090716.pdf here].
		+
		+	==8/31/2016==
		+
		+	Present: Ryan, Toby, Ellie, Karl, Jixie, Vince, Jie, Alexandre, JP <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Jie
		+	Gave an update on the BPM pedestal analysis. He showed results from the pedestal analysis of beam trip runs for both the Happex DAQ and HRS DAQ.  HRS DAQ has cleaner pedestals but the HRS DAQ is less precise.  The pedestal shift seen in the HAPPEX DAQ is continuos with time. He will continue to look at the BPM calibration procedure and try and quantify the effect the pedestals have on the BPM uncertainty. More details can be found in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_08_28_plots_eps/yields_update_20160831.pdf here].
		+
		+	Verbal Updates:
		+	*Ryan
		+	Continuing to look at HRS asymmetry angle dependence
		+
		+	==8/24/2016==
		+
		+	Present: Ryan, Toby, Ellie, Chao,  Vince, Jie, Alexandre, JP <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Toby
		+	Showed an update on the packing fraction analysis. He has been able to successfully fit the two elastic peaks (N2 and He4) and quasi-elastic peak to produce packing fraction results. He also presented an alternative calculation to the packing fraction, just using the helium peak from production and a dummy/empty run. His two methods agree at the ~10% level but differ greatly from what Melissa showed previously. Toby will continue to look at his fits and see if there is room for improvement there because there is some fit dependence on the result. One suggestion was to fit the simpler dummy run He4 elastic peak and use those fit parameters in the production runs. More details can be found in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/pf_update.pdf here].
		+
		+	Verbal Updates:
		+	*Ryan
		+	Continuing to look at HRS asymmetry angle dependence
		+
		+	*Jie
		+	Working on understanding Pengjia's BPM code.
		+
		+	==8/17/2016==
		+
		+	Present: Ryan, Toby, Ellie, Chao,  Vince, Jie, Alexandre <br>
		+
		+	'''Feature Presentations'''
		+
		+	*Ryan
		+	Showed a comparison between asymmetries between LHRS and RHRS for the three 5T settings: 2.2 GeV long/trans and 3.3 trans. Overall there is good agreement between the HRS's, and the biggest disagreement is between the arms at the 2.2 GeV trans setting. Ryan will check that scattering angle dependence of the asymmetries next to see if this can improve the agreement. Currently the RHRS scattering angle reconstruction is not correct. Chao believes this is a coordinate system issue in his code. Slides can be found [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_081716.pdf here].
		+
		+	Verbal Updates:
		+	*Chao
		+	Back at JLab for one year. First thing he will focus on is correcting the scattering angle reconstruction for the RHRS replay. After this he will move onto the acceptance study for the 5T longitudinal setting.
		+
		+	*Jie
		+	Working on understanding Pengjia's BPM code.
		+
		+	*Toby
		+	Working on updating the target polarizations for the HRS's. Found a bug in his code in converting UNIX times. Also developing two parallel methods to determine packing fraction, one using fits and another using simulation.
		+
		+	==8/03/2016==
		+
		+	Present: Ryan, Toby, Karl, Vince, Jie, Alexandre <br>
		+
		+	No Presentations.
		+
		+	Verbal Updates:
		+
		+	*Jie
		+
		+	Got code for BPM calibration from Pengjia. Still waiting on some further explanation from Pengjia on the code. He will focus on the 5T settings first in the calibration
		+
		+	*Toby
		+	Working on the g2psim package and using it for calculating the packing fraction. Replayed  RHRS 5T transverse data, and according to Chao it should have final optics.
		+
		+	*Ryan
		+	Has a working model dilution code.
		+
		+
		+	==7/27/2016==
		+
		+	Present: Ryan, Toby, Jie, Vince, Kalyan,  JP, Karl <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Jie
		+	Working on trying separate two peaks in the BPM pedestal runs.  It does not appear that the two peaks can be filtered based upon the frequency using an FFT. Moving forward he will check how the double peaks affect BPM calibration uncertainty and check the BPM calibration procedure. More details can be found in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_0723_plots/yields_update_20160727.pdf here]
		+
		+	*Ryan
		+	Presented raw asymmetries with three difference acceptance cuts to highlight the angle dependence on the asymmetry in the delta-region. Was able to produce a similar trend in models using scattering angles from the data. Going forward will try to find acceptance cuts that select similar numbers of events and see if the ratio between data points is the same as the ratio of model points to do a bin-centering type correction. More details can be found in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_072716.pdf here]
		+
		+
		+	==7/20/2016==
		+
		+	Present: Ryan, Toby, Jie, Vince, Alexandre , Kalyan, Karl, Ellie  <br>
		+
		+	Verbal Updates:
		+
		+	*Jie
		+	Looking into 2-peak pedestal issue for the BPMs. Checking to see if the two peaks are at different frequencies and can be separated. If they cannot then the 2-peak pedestals will increase the BPM reconstruction uncertainty at the target to ~3-4mm (from 1-2mm) for runs with the double peak. Previously Pengjia did not consider any RMS value above 2000 in his analysis.
		+
		+	*Toby
		+	Still working on getting the g2p simulation package to match g2p data. Able to now produce elastic peaks in the correct locations to match data. Requesting that someone familiar with g2psim make a post on the wiki detailing the variables in the output of the simulation root tree because they are not straight-forward to understand.
		+
		+	*Ryan
		+	Completed setting up a python version of the radiated model code. Uses MAID/Hall B for the polarized and Bosted for the unpolarized. Does the unpolarized and polarized elastic tail but only uses RADCOR for the inelastic radiating.
		+
		+
		+	==7/13/2016==
		+
		+	Present: Ryan, Toby, Jie, Vince, Alexandre ,  JP, Karl, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Jie
		+	Showed a comparison between the BPM pedestals calculated during dedicated pedestal runs and during beam trips. The two methods agree, so Jie is moving forward with the beam trip method to fill in gaps for BPM pedestal calculations. His next step is to move onto checking the BPM calibration. More details can be found in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_0710_plots/yields_update_20160713.pdf here]
		+
		+	Verbal Updates:
		+	*Toby
		+	Still working on getting the g2p simulation package to match g2p data. This will be used for calculating the packing fraction
		+
		+	*Ryan
		+	Working on producing radiated models to compare to the g2p data.
		+
		+
		+	==7/6/2016==
		+
		+	Present: Ryan, Jie, Kalyan,  JP, Karl, Ellie  <br>
		+
		+	Verbal Updates:
		+
		+	*Jie
		+	Working on comparing pedestal values from dedicated pedestal runs and from beam-trip's. He's mostly found agreement and is working to settle the few outliers. After this he is moving onto to checking the BPM calibration.
		+
		+	*Ryan
		+	Working on setting up radiated models to compare with the radiated data asymmetries.
		+
		+
		+	==6/29/2016==
		+
		+	Present: Ryan, Toby, Jie, Vince, Kalyan,  JP, Karl, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Jie
		+	Gave an update on the BPM pedestal issues. In his slides he shows the pedestal histograms to demonstrate that the pedestal value is really shifting with time. Some pedestal's also exhibit a multi-peak structure, which ultimately will effect the uncertainty of the BPM calibration. He also showed the effect of using different BPM pedestal values for different runs and effects the BPM reconstruction. The resulting BPM position change is much larger than simulation would predict indicating that again that the BPM pedestal value is really changing with time. Going forward he will look to determine an accurate BPM uncertainty from the fluctuating pedestal values. More details on his slides can be seen [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_0627_plots/yields_update_20160629.pdf here].
		+
		+	Verbal Updates:
		+
		+	*Toby
		+	Working on updating Melissa's packing fraction code to use simulation to match the quasi-elastic peak, instead of relying on fits because the packing fraction result is highly-sensitive to the fit parameters.
		+
		+	*Ryan
		+	Working on raw asymmetries and comparing them with Toby to make sure they agree.
		+
		+	*Vince
		+	Has updated ChiPT calculations that he will send out over the mailing list.
		+
		+
		+	==6/22/2016==
		+
		+	Present: Alex, Ryan, Toby, Jie, Vince, Kalyan  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Toby
		+	Received Melissa's packing fraction code. Found that there is now a difference in the nu histograms for the elastic runs when compared to what Melissa used in her analysis. Melissa's tech-note shows only a single elastic peak, but new root-files have both a elastic nitrogen and helium peak. The two peaks are separated by about 5 MeV at E0 = 2.2 GeV. The existence of an additional peak effects the applicability of Melissa's fitting routines to these new root-files. Toby will contact Melissa and see what she can provide. Slides are [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/elasticyield_talk.pdf here].
		+
		+	Verbal Updates:
		+
		+	*Jie
		+	Jie is still talking with Pengjia over the BPM pedestal issue. He hopes to have slides for next week's meeting.
		+
		+	*Ryan
		+	Ed Folts confirmed the presence of helium bags in the septum bores and local dump box. In contact with Jessie Butler to find Ed's old pictures of the g2p target platform. Assuming helium is present in radiation thicknesses after scattering. Will update if there is any change. Tech-note with the radiation lengths can be found [https://userweb.jlab.org/~rbziel/g2p_radlengths.pdf here]
		+
		+
		+	==6/15/2016==
		+
		+	Present: JP, Karl, Alex, Ryan, Toby, Chao, Jie, Vince, Ellie, Xiaochao, Kalyan  <br>
		+
		+	No presentations. Just verbal updated
		+
		+	*Jie
		+	Jie gave a little more detail on the carbon cover from last week's slides. The carbon cover is a porous carbon sponge added to the BPM to help with radiation. This in itself shouldn't effect the pedestal but opening up the BPM to install it could have an effect. It's possible the pedestal change is also related to configuration changes in the target magnetic field. Jie will show more at meeting next week.
		+
		+	*Ryan
		+	Confirmed from Chao that DP is not corrected for ELOSS. Still waiting to hear back from Ed Folts on g2p helium bags.
		+
		+	*Toby
		+	Getting Melissa's packing fraction code this week. Will use it to update packing fraction calculations.
		+
		+
		+	==6/8/2016==
		+
		+	Present: JP, Karl, Alex, Ryan, Toby, Chao, Jie, Vince, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Ryan
		+	Gave an update on the radiation length calculation. He checked the energy loss calculation people did before and found out that we did not use the He bag during the experiment but before people built the He bag in the simulation. However the difference between He and air should not cause serious problem for us. More details can be seen in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_060816.pdf here].
		+
		+	*Jie
		+	Gave an update on the beam position problem. He worked together with Pengjia on this problem. The bpm database is updated so that the beam current dependence of the BPM is removed. Another problem is that the reported beam position would jump suddenly within the same momentum setting. Pengjia and he guess the pedestal of the BPM might be a possible reason. And between the two run they compared, a carbon cover was added which might influence the pedestal. So they did some study of the BPM pedestal values. The current cut Pengjia used before to select no-beam events is replaced by a more tight one. However, the results do not change much. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_0608_pedstal/yields_update_20160608.pdf here].
		+
		+
		+	==5/25/2016==
		+
		+	Present: JP, Alex, Ryan, Toby, Chao, Jie, Vince, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Toby
		+	Gave an update of his study on the scattering angle. The problem he mentioned on 5/11 has been solved. Both of the formulas are correct. However, he found that the central scattering angle jumped within one momentum setting for more than 3 deg. Chao mentioned that his calculation result does not show this behavior and they will discuss this offline. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/scatangle_talk_5.25.16.pdf here].
		+
		+
		+	==5/18/2016==
		+
		+	Present: JP, Karl, Alex, Ryan, Toby, Chao, Jie, Vince, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Chao
		+	Gave an update of the acceptance study. He used the elastic scattering data to calibrate the resolution of the simulation. He found that the simulation package does not treat the resolution of the beam position properly. Thus the simulation package is updated to generate the events according to the beam profile. With this new update, the resolution of the simulation agrees with the data. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/chao/20160518/Chao_WeeklyMeeting_05182016.pdf here].
		+
		+
		+	==5/11/2016==
		+
		+	Present: JP, Karl, Alex, Ryan, Toby, Jie, Vince, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Toby
		+	Gave an update of the scattering angle calculation. He used two formulas from Pengjia and Chao to calculate the scattering angle and suggests that the results do not agree. People suggests that this two methods are equivalent and we should just use one of them. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/scatangle_talk_5.11.16.pdf here].
		+
		+	*Ryan
		+	Gave an update of his study of the scattering angle dependence of the cross-section. He used the radiated Bosted model and calculated the cross-sections with three different scattering angle. And the results shows ~20% difference. More details can be seen in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_051116.pdf here].
		+
		+	*Jie
		+	Gave an update on his study of the yield drift problem. He is still working together with Pengjia to correct the beam current dependence of the beam position. He summarized the beam current distribution for all production runs and found that ~90% of our data was taken with current less than 50 nA, where the beam position need to be corrected. He also studied the "sudden jump" of the beam position which means that the BPMA and BPMB readout did not changed much but the reported beam position changed a lot. It probably could be explained by the pedestal change but still need more study. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_0508_plots/yields_update_20160510.pdf here].
		+
		+
		+	==4/20/2016==
		+
		+	Present: JP, Karl, Alex, Chao, Ryan, Toby, Jie, Vince, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Ryan
		+	Gave an final update of the nitrogen cross-section study of the saGDH experiment. The radiative correction is done and the uncertainty carry-over from the elastic tail analysis is 1.5%. The radiative correction is calculated in two different way: the classic unfolding and the ratio of un-radiated and radiated Bosted model. He also did a bin center correction and compared the result with Vince's calculation. Two methods agrees at a 1-2% level. The radiative corrected cross-section for each kinematics setting is summarized in his slides and he will prepare a tech note for the analysis. More details can be seen in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_042016.pdf here].
		+
		+
		+	==4/13/2016==
		+
		+	Present: Karl, Chao, Ryan, Toby, Jie, Vince, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Jie
		+	Gave an update on his study of the yield drift problem. Last time he showed some plots which indicates that the beam position might not be accurate and he did some study on this problem. He found out that the BPM readout shows some linear relations with the beam current. After carefully check the data, it seems that only the BPM B have this correlation. And this problem could be found in all beam energy settings. The uncertainty of beam position is very large if this problem is not corrected. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_0404_beamcurrent_plots/yields_update_2016_04_13.pdf here].
		+
		+	*Ryan
		+	Gave an correction to his presentation on last week. He mentioned there was a mistake when he compared the formulation for the full internal bremsstrahlung tail and the angle-peaking approximation. And the results agree after the mistake was corrected. More details can be seen in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_041316.pdf here].
		+
		+
		+	==4/6/2016==
		+
		+	Present: JP, Karl, Chao, Ryan, Toby, Jie, Vince, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Ryan
		+	Gave an update on his radiative correction study. He already studied the uncertainty for the elastic tail and he continued his study with the inelastic radiative correction. He explained how the angle approximation was applied in the internal bremsstrahlung. There is an equivalent correction in the angel approximation which is dropping the soft photons compare with doing a full integration. Difference between these two calculation is 5-10% for proton. He is still working on applying the calculation to other nuclei like Nitrogen. More details can be seen in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_040616.pdf here].
		+
		+	*Toby
		+	Gave an update on the his calculation of the asymmetry and cross-section. He applied the dilution factor calculated from the data to the asymmetry calculation. On the other side, he also applied the radiative correction factor calculated from the MAID model to the asymmetry calculation. He then applied the same factors to the cross-section calculation and got the cross-section and cross-section differences. The dilution seems not continuous and JP suggests to do a deeper study for each momentum in the longitudinal setting to understand what is the reason, for example the yield problem studied by Jie. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/asym_xs.pdff here].
		+
		+
		+	==3/23/2016==
		+
		+	Present: JP, Karl, Chao, Ryan, Toby, Jie, Vince, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Jie
		+	Gave an update on his study of the yield drift problem. He continued his study with dilution runs. The method he used is similar as what he did for the production runs. He made a 6mm radius circle cut and compare the simulation result with the data. There are a few runs which were measured with beam current less than 50nA. After discussion with Pengjia, Jie mentioned that those runs' BPM readout might not be accurate since the BPM is calibrated at 50nA~100nA. He will do further study together with Pengjia to understand this effect. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_03_22_plots/yields_update_2016_03_23.pdf here].
		+
		+
		+	==3/9/2016==
		+
		+	Present: JP, Karl, Chao, Ryan, Toby, Jie, Vince, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Toby
		+	Gave an update on the dilution study. He summarized the dilution calculation for the 2.2GeV 5T transverse settings. He also used the dilution result to calculate the asymmetry for this setting. The radiative correction was considered in the calculation. And he concluded that the uncertainty of the calculation is dominated by the packing fraction uncertainty. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/asymtalk_030916.pdf here].
		+
		+	*Ryan
		+	Gave an update on his cross-section analysis of the small angle GDH data. Based on the discussion from previous meetings, he checked the uncertainty of the elastic tail. The calculation includes three different sources: the correction factor representing higher order virtual photon diagrams, bremsstrahlung and multiple photon corrections. For the multiple photon corrections, he mentioned that G.Miller has an alternative multiple photon correction result. He applied the calculation to the saGDH data and it seems that the Miller multiple photon result is better representation of saGDH elastic tails. More details can be seen in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_030916.pdf here].
		+
		+	*Jie
		+	Gave an update on his study of the yield drift problem. He and Pengjia fixed the problem in the raster size calculation. He then made some cuts on the raster size to remove the boundary effect. He mentioned some of the runs had hot spot and was able to be corrected by the raster cut. He also summarized the yield spread with raster cuts for all kinematic settings. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/jie/2016_03_01_raster_plots/yields_update_2016_03_09.pdf here].
		+
		+
		+	==2/24/2016==
		+
		+	Present: Karl, Chao, Ryan, Toby, Min, Ellie, Jie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Toby
		+	Gave an update on the dilution study. He need the scattering angle to calculate the scaling factor between the carbon and nitrogen. However, his study suggests that the scattering angle calculated for the carbon target is larger than the production target. The simulation shows opposite result which is expected to be reasonable from geometries. People suggests Chao to check the scattering angle calculation in the optics package. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/scatangle_dilution_022416.pdf here].
		+
		+
		+	==2/17/2016==
		+
		+	Present: JP, Jixie, Chao, Ryan, Min, Ellie, Jie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Chao
		+	Gave an update on the optics study. He finished the matrix recalibration on right arm. The database is updated and is ready to use. The RMS values for angle and momentum calibration are summarized in his presentation. JP and Jixie has some concern about the broken septa seems to cause worse effect on left arm comparing with right arm. They suggested to check this more carefully. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/chao/20160217/Chao_WeeklyMeeting_02172016.pdf here].
		+
		+	*Ryan
		+	Gave an update on his cross-section analysis of the small angle GDH data. Based on the discussion from the last week's meeting, he removed the extrapolation part in RADCON and then test the code with some test cross-sections from Pbosted Model. There is no problem in this case. So he compared the Pbosted model with saGDH data at large <math>\nu</math>. He is waiting for the response from Vince about the uncertainty of the saGDH cross-section at large <math>\nu</math>. More details can be seen in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_021716.pdf here].
		+
		+
		+	==2/10/2016==
		+
		+	Present: JP, Karl, Alex, Jixie, Toby, Chao, Ryan, Min, Ellie, Vince  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Ryan
		+	Gave an update on his cross-section analysis of the small angle GDH data. He is dealing the problem that after doing the tail subtraction and radiative correction the cross sections go negative at high <math>\nu</math>. He did a refit of the few low <math>Q^2</math> points using a charge form factor fit. The results still deviated from the PBosted model at high <math>\nu</math>. However, JP and Karl suggests that the code RADCOR code should not give negative cross section result. There might be some problems in the extrapolation part. Karl suggests to check the input data to see if there are constrains at the high <math>\nu</math> region. More details can be seen in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_021016.pdf here].
		+
		+
		+	==2/3/2016==
		+
		+	Present: JP, Karl, Alex, Jixie, Toby, Jie, Chao, Ryan, Ellie, Vince  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Min
		+	Gave an update on her acceptance study. She continued to compare the simulation result with data.  Since the optics database is updated with the vertical beam position correction. The result suggests that the delta distribution is improved however the phi distribution still shows large discrepancy. She used this result to calculate the acceptance factor and applied it to the cross-section calculation. The result shows a factor of two difference. JP suggests that the acceptance calculated from the compare between the simulation and the data could still be influenced by the cross-section difference at small scattering angle. More details can be seen in her slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/mhuang/acceptance/02032016.pdf here].
		+
		+	*Toby
		+	His presentation on 1/12 is reviewed. JP mentioned his concern about the uncertainty propagation. Toby is going to check it again and update his tech note about it.
		+
		+	'''General Discussion:'''
		+
		+	*The replay package is restored on the work disk.
		+	*Toby will talk to Melissa and take over her packing fraction study.
		+
		+
		+	==1/26/2016==
		+
		+	Present: Jixie, JP <br>
		+	By Phone: Jie, Chao, Ryan, Ellie  <br>
		+
		+	'''General Discussion:'''
		+
		+	*The analysis meeting will be moved back to '''10 am Wednesday''' starting from next week.
		+	*There is no meeting room available thus everyone will join by bluejeans. The meeting ID is 4828802914.
		+
		+
		+	==1/12/2016==
		+
		+	Present: Melissa, Jixie <br>
		+	By Phone: Jie, Chao, Ryan, Toby, Ellie  <br>
		+
		+	'''Feature Presentations:'''
		+
		+	*Ryan
		+	Gave an update on his cross-section analysis of the small angle GDH data. yield study using simulation. He is working on the problem that after doing the tail subtraction and running the inelastic Radiative Correction code the fully corrected cross sections go negative at high <math>\nu</math>. To solve this, he did a fit on the Nitrogen form factor. During the fitting, two models is considered: the oscillator model and the Fermi Model and the Fermi Model is proved to be better. He will complete the calculation of the elastic tail by using the form factor in a few weeks. More details can be seen in his slides [https://userweb.jlab.org/~rbziel/Weekly_Meetings/g2p_011216.pdf here].
		+
		+	*Toby
		+	Gave an review on the polarization uncertainty estimation. He claimed that the reason of the small uncertainties for the target polarization is because we took large amount of TE for each material. Thus the uncertainty of the calibration constant is reduced by average. Jixie suggests that the error propagation still need to be carefully checked. More details can be seen in his slides [http://hallaweb.jlab.org/experiment/g2p/collaborators/toby/g2p%20meetings/targunc.pdf here]
		+
		+	'''General Discussion:'''
		+
		+	*Chao updated his optics technical note.
		+	*There is no meeting next week due to the Hall A collaboration meeting.
−	*Pengjia:
−	1) Continue working on the remote control program for the function generator
−	*Kalyan:
−	1) Continue designing the 3rd arm <br>
−	2) Got confirmed from Al that 3rd arm can not be used in GEP
−
−	*Jixie:
−	1) Learning the optics from Nilanga, will meet with Vince to discuss the optics plan <br>
−	2) Tried to test the magnetize effect of the translation table. Replaced some steel bolts and nuts <br>
−	with plastic ones. Toby and Chao will make a coil to test the stainless steel. <br>
−	3) Running simulation to get local beam dump opening for Al.  But the HRS transportation routines
−	from Min do not work. <br>
	----		----
		+	==Jul-Dec 2015==
		+	[[Minutes_Jul2015_to_Dec2015]]
		+	----
		+
		+	==Jan-Jun 2015==
		+	[[Minutes_Jan2015_to_June2015]]
		+	----
		+
		+	==Jul-Dec 2014==
		+	[[Minutes_July2014_to_Dec2014]]
		+	----
		+
		+	==Jan-Jun 2014==
		+	[[Minutes_Jan2014_to_June2014]]
		+	----
		+
		+	==Jun-Dec 2013==
		+	[[Minutes_June2013_to_Dec2013]]
		+	----
		+
		+	==Jan-May 2013==
		+	[[Minutes_Jan2013_to_May2013]]
		+	----
		+
		+	==April-Dec 2012==
		+	[[Minutes_Apr2012_to_Dec2012]]
		+	----
		+
		+	==Jan-Mar 2012==
		+	[[Minutes_Jan2012_to_Mar2012]]
		+	----
		+	==Jul-Dec 2011==
		+	[[Minutes_July2011_to_Dec_2011]]
		+	----
		+	==Jan-Jun 2011==
	[[Minutes_Jan2011_to_June_2011]]		[[Minutes_Jan2011_to_June_2011]]
	----		----

---

Latest revision as of 11:57, 29 July 2021

Minutes of the weekly analysis meetings

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Agenda

07/29/2021

Present: JP, David

• David showed a zoomed in plot of the Q^6 Delta_LT scaling agreed upon last week, and JP and David both agreed that this made the high point look unnecessarily bad. David agreed to make a similar version of the Q^4 plot to decide between next week, and include the Q^6 plot in the current paper draft.
• David mentioned that he found Chao's internal presentation of an elastic study which yielded a contribution to the acceptance systematic of 4%. JP commented this was likely to be the dominating systematic for the acceptance and suggested that David use this to obtain a back of the napkin calculation of the XS systematic. JP also suggested that this systematic could be representative of our overall uncertainty in the 1.15 scaling to match the g2p data to the Bosted model, and that we could potentially quote this number to anyone who raises issue with the scaling factor.
• There was a brief discussion of the Drechsel paper JP found, he suggested Karl would probably have access and that the discussion in that paper would likely feed what we should say about d2 in our paper.
• David mentioned that he has been working this week on making a draft of the paper with Karl's comments from last week and JP's comments from this week, and would try to finish in the next day or two to send to the Spokespeople.
• David will be traveling next week but available for a meeting, JP suggested if the draft was sent out this week it would be a good time for a short meeting for Karl, JP, and any others to share their current thoughts and comments on that iteration of the draft.

07/22/2021

Present: Alexandre, JP, Karl, David

• David showed a number of slides showing delta_LT multiplied by various powers of Q2. We commented that Drecschel shows Q6/M2 delta_LT in his paper. Also the 2004 E94010 polarizabilities showed the same quantitty. So there is precedent for this. David will produce a zoomed version of the plot. He also showed delta_LT/gamma_0, although he has low confidence in the present error bars. He will revisit and he and Karl will try to add RSS data, Maid and pdfs to see if the transition to the predicted scaling at very large Q2 is at all visible at this very low Q2.
• JP Asked David to look at threshold again, and to try to dig out Chao's evaluation of the acceptance uncertainty from the elog and old wiki presentations.
• Alexandre reminded that there is a lot of good old information in the elog : https://hallaweb.jlab.org/dvcslog/g2p/
• We switched the weekly meeting time to 10:30am on Thursdays.
• Karl will be on travel next week, but expects to be available for the weekly meeting.

05/01/2019

Present: JP, Karl, David Feature Presentations :

• David

Showed a number of slides building up the 2.5T 2.2GeV dilution one step at a time to try and analyze any outstanding issues. These plots showed severe edge effects from the momentum settings on all run types. J.P. and Karl suggested fixing this by doing a fit to one of the yield, and then using an offending momentum setting to find a dp correction to the fit and apply it everywhere. The plots also showed several momentum settings where the centroid appeared to be shifted, David promised to do some detective work to try and figure out why.

Verbal Updates:

None

12/06/2018

Present: Karl, Chao, David Feature Presentations : None. Verbal Updates:

• David

Discussed a final issue with Chao leading to simulated peaks being smeared too wide, because of a smearing parameter in the input file being too big. Said he should have final 5T Longitudinal packing fractions next week, and is prepared to have final 2.5T 2.2GeV packing fractions once Snake Model is complete. Also showed a plot of Gamma 2 indicating that the cost to using just the Material 8 data for the 2.2GeV 2.5T would be costly, more than doubling the total error bar and changing the central value slightly, highlighting the need to use one of the other methods discussed to complete the analysis.

• Chao

Chao said that he will be needing to leave the field and seek a job in industry starting in January, but said he would finish updating the Snake model before he goes so that the packing fraction analysis can be completed with the new method.

10/04/2018

Present: J.P., Karl, Chao, David Feature Presentations :

• David

Showed several slides on the current status of the 2.5T packing fraction. With several issues fixed, the carbon peak shows good agreement with the helium peak subtracted by using a helium simulated elastic peak and subtracting it scaled by the appropriate packing fraction. For the production data, this process was repeated with an iterative process for the packing fraction of helium, showing no sensitivity to initial guess and converging on relatively reasonable packing fraction results. J.P. and Karl suggested that the fit between the simulation and the data is not perfect, it may be a reasonable enough comparison to function. However, for Material 7, the elastic yield is much sharper than for Material 8, and while the latter matches the shape of the simulation well, the former looks very different. Karl suggested to look into how the materials compare to the simulation for other settings, and J.P. noted that it should be impossible to compare the integrated yield to the simulation if their shape is different. It was also suggested to check on the status of the septa, and see if the simulation has accounted for any possible changes in it.

09/27/2018

Present: J.P., Karl, David Feature Presentations :

• David

Showed several slides on the current status of the 2.5T packing fraction. Showed first a carbon slide showing better agreement, but still a few very jagged areas in the simulated carbon peak, and mentioned that he has defaulted to comparing dilution data with helium in it, as the optics data proved very hard to work with. J.P. mentioned that in addition to the jagged behavior at the top of the peak, it is worth looking into why the simulation peak seems wider than the production data very slightly at the base. Using the scale factor provided by this carbon comparison, David showed several slides of the resulting packing fractions, doing a linear fit to an 0.4 and 0.6 packing fraction simulated yield. J.P. and Karl gave several suggestions for dealing with the Helium elastic peak, since that has not been done yet. J.P. also suggested it was a good idea to take the whole Nitrogen peak when integrating to find the packing fraction, rather than just part of it. David mentioned he would also talk to Chao about the odd behavior at the top of the elastic peaks and ask for suggestions. The packing fractions at this stage seem to give reasonable values, though everyone commented it will be important to subtract the Helium elastic peak before finalizing the packing fractions, and apply this same method to one of the 5T energy settings to compare to Toby's Ratio method.

Verbal Updates:

None

09/13/2018

Present: Chao, J.P., David Feature Presentations :

None

Verbal Updates:

• Chao

Working on smoothing out the acceptance correction for the 5T Transverse 2.2 GeV energy setting.

• David

Showed a few slides, indicating that the proper cuts give very good agreement for the carbon data in the elastic region. However, it was discussed that there are many jagged peaks above this region that Chao says should not exist. Chao gave a few suggestions for improving the simulation's agreement. David also asked about how to scale properly by the luminosity, and how to actually put the packing fraction in the simulation, as the setting in the simulation only changes the energy loss according to Chao. J.P. and Chao explained that David should just scale the 0.6 packing fraction simulation by 0.6, and so on, but that each element would need to be scaled separately and added together (so for 0.6 packing fraction, total yield = 0.6 Nitrogen + 0.4 Helium + 0.6 Proton, etc). J.P. also suggested to try simulating an empty cell as the helium peak should be clean and match well.

08/09/2018

Present: Chao, Karl, David Feature Presentations :

None

Verbal Updates:

• Chao

Working on finishing transverse data, doing another replay, save root files on his local computer so it will not be diluted anymore, will calculate transverse acceptance soon. Won’t be at meeting next week, in two weeks will show final 5T 2.2 GeV transverse acceptance.

• David

Working on comparison between carbon g2psim and data for 2.2GeV 2.5T, asked Chao a few technical questions about weighting the g2psim histograms in C++ or Python.

08/02/2018

Present: Chao, J.P., Karl, David Feature Presentations :

• Chao

Chao showed a few slides of final longitudinal acceptance correction, which he said look good except for a discontinuity at the start of the quasi elastic peak for longitudinal. Karl suggested checking the same plots with no dp cut just to compare. Chao also suggested that we make a repository of all g2p codes and simulations so that we can easily access whatever we need.

Verbal Updates:

• David

David mentioned that he’s working on learning to use g2psim with Chao’s help, so that he can tweak it and produce simulated yields for use in the Oscar PF method.

07/26/2018

Present: Chao, Karl, David Feature Presentations :

None

Verbal Updates:

• David: thanked Chao for sending g2psim, asked a few technical questions about operating it. Chao noted that it’s important to run each material seperately, so for production data, to run nitrogen, hydrogen, and helium independently and convolute them. David also showed the functional form of the uncertainty in g2 as a function of the uncertainty in the packing fraction, Karl suggested to provide rough numerical values and David agreed to do so next week.

• Chao: Sent David the current working version of g2p sim, very nearly done with 5T longitudinal acceptance. Will show cross sections for 5T longitudinal next week.

07/19/2018

Present: Chao, J.P., Karl, David Feature Presentations :

• Karl

Karl started off with some overview slides to try and get a majority of the work done by the end of the summer before people get busy. He voiced that the biggest question is whether we are using a data or model cross section, where the data is the attractive option if possible to make our results model independent, but the model may be a better option if the data is impossible or will take too long, as we can more or less publish the 5T data now, and the 2.5T data (pending pf analysis) He also asked if by the end of the meeting, we could identify all outstanding tasks and give an estimate for how long they will take to complete. Barring december, said that we should plan to have a paper submitted to PRL by the end of the year.

Moments paper work to be done yet: Low x contribution to BC integral Low nu contribution to gamma0

• David

David showed a talk describing the Oscar Rondon packing fraction method. J.P. voiced that since the method requires scaling the simulation to carbon data, it cannot be used in the elastic region since you would need a different scale factor for carbon or nitrogen, so the only region to apply the method is the very inelastic one. Chao said right now he doesn’t think the simulation can do inelastic data, but that once he applies Ryan’s tweaked Bosted model, he thinks it will be able to. There was some discussion about the error bar for this packing fraction method, and J.P. said that the standard deviation of both the carbon and the production data in the chosen region would need to be applied to get the total error.

There was brief discussion of going back to the unfinished elastic fit method if all else fails, since all that should need to be done is finding a way to deal with quasi elastic contamination.

David also showed plots for the scattering angle for 2.5T 2.2GeV that show that even once the materials are separated out, all the data seems choppy at high E’ values.

Verbal Updates:

• Ryan

Finally, David relayed a few questions from Ryan. Karl said he doesn’t care which paper is published first and we should just publish them in the order we are able to. He also voiced that Ryan’s hyperfine question was something we could discuss offline or at the next meeting as time ran short. With regard to the question of using our cross sections, the eventual conclusion was that if Chao is able to match the timetable he provided today that it may be feasible to use g2p cross sections for all 2.2GeV energy settings.

• Chao

Chao says within 2 weeks he can get cross section for longitudinal. Estimates within 1 month will have acceptance for 2.2 GeV, 5T Trans+Long, and another 6 weeks for 2.2GeV, 2.5T Trans. He said that 3.4 GeV has no elastic so he’s not sure there will be an acceptance. Karl and JP suggested he then prioritize the three 2.2GeV settings.

David estimated 6-7 weeks to get the packing fraction assuming we can get simulated yields. Chao agreed to send g2p simulation package to David so he can help with adding in missing models (Ryan Bosted-tweak?) and start learning to use it for applying the Oscar Method.

07/12/2018

Present: Chao, J.P., Karl, Ellie, David Feature Presentations :

• Karl

Showed the plots that he showed at Trento, and mentioned that there is a lot of interest right now specifically in the hyperfine result, as Ryan's calculation of delta 2 disagrees noticeably with the most recent papers. Said that we should try and get the paper out by the end of the year, so we should try and finish both acceptance and pf by the end of summer. Suggested that next week we sit down to figure out a game plan for how to do that.

Verbal Updates:

• David

Mentioned that he and Karl got in touch with Oscar Rondon to ask a few questions about his packing fraction method, which we hope to try. Also said that he is currently re-playing the packing fraction rootfiles for several gradations of cut in case we want to study the cut dependence of the ratio method. Also working on producing plots for the scattering angle fit for just the carbon data, and for each production material independently. Karl asked Chao about how good the simulation is for the transverse settings, Chao said he has been focusing on the simulation for the 5T 2.2GeV settings but could maybe look into it.

• Chao

Chao said he is continuing to work on the acceptance, and has been looking into the super-elastic peak J.P. asked about last week. 

05/31/2018

Present: Chao, J.P., Karl, Ellie, David Feature Presentations :

• Chao

Fit correction to the yield for 7 momentum settings in quasielastic region. Checked if the correction is stable and showed plot of yield for a 2.2GeV 5T run with the correction applied. J.P. says effective correction should be fine to fix relative difference. Discussed discontinuity at nu = ~459 MeV, Chao said he can fit that region to try and remove it. Karl asked about the motivation for the correction, Chao explained it is a fit that he found that works. See agendas section for plots.

Verbal Updates:

• David

Still trying to work on packing fraction analysis. Modified code from Toby to re-add 5T settings, can nearly reproduce Toby's results but scaled down by a factor of 3.5 for all 5T energy settings. Sent an email to Toby and trying to look into what variable change could cause this difference between 2.5T and 5T.

05/24/2018

Present: Chao, J.P., Karl, David Feature Presentations :

None

Verbal Updates:

• Chao

Still working on data corrections for the acceptance discontinuity, will have results next week. Also looked into beam position and found how to retrieve data from EPICS to help David, though warned that this does not give the real beam position, but the beam jumps should still show up in the raw data.

• David

Working on packing fractions and the to-do list of suggestions Ryan left last week, is able to reproduce Toby's ratios, working on doing a fit to the scattering angle to determine how the simulation might change with the tighter cut. J.P. suggested that taking the average scattering angle required correcting the data to an average as well. David also mentioned that he fixed the issue with getting null results from Toby's code for 5T, but still cannot reproduce the 5T packing fractions correctly.

05/17/2018

Present: Chao, J.P., Karl, David Feature Presentations :

None

Verbal Updates:

• David

Showed a few plots of the spread and average for each momentum setting involved in the asymmetry discrepancy analysis for the 2.5T data. However, J.P. noted that some of the means didn't quite make sense given the error bars of the points involved, and it became clear that there were a few mistakes in the normalization of the parameters for these plots. Further, differences between the global run by run asymmetry plot and the momentum-setting ones lead to the conclusion that there must have been a mistake in the presentation of the plots. David said he would re-do this section of the analysis more carefully and try again next week to determine if any of the momentum settings seem pathological.

04/26/2018

Present: J.P., Karl, David Feature Presentations :

None

Verbal Updates:

• David

Showed a reprisal of his update on the Left and Right HRS Asymmetry comparison for the 2.2 GeV 2.5 T data to catch J.P. up, and mentioned that he will produce a plot of total asymmetry plotted against run number by using a run by run asymmetry, at Ryan's suggestion. J.P. and Karl both agreed that it would not be wholly unacceptable to add a systematic to the moment data if the issue could not be resolved otherwise, but that it would be ideal to solve it and not have to do that. J.P. also suggested that since the asymmetry seems to be unstable for both arms around the relevant point, that perhaps something happened with the beam, and suggested cross comparing to Jie's BPM analysis to try and determine if there was a beam jump or something similar around the time that the inconsistency occurs. Also showed a table of packing fractions generated from Toby's scripts with different acceptance cuts. Said that the inclusion/exclusion of the RunStatus 6 Packing Fraction runs seems to have little impact on the Packing Fractions generated, but that using Ryan's tight cut in place of any of Toby's loose cuts produces packing fractions for the 2.2 GeV 2.5 T setting that seemed to Karl to be more reasonable. J.P. and Karl both suggested that one standard cut should be used for everything, preferably Ryan's tight cut since that has been well documented and discussed already. David said he will produce a re-done version of Table 6.4 from Toby's thesis, with all of the packing fractions generated using Ryan's tight cut.

04/05/2018

Present: Chao, David Feature Presentations :

None

Verbal Updates:

• Chao

Still working on trying to resolve acceptance issue, before J.P. left for China he advised that Chao try cuts on various variables that go into the acceptance, like the Raster and the BPMs, to try to quantify what the effect on the acceptance is. Chao said he is currently working on doing this.

• David

Said that he compared error bar on Gamma 2 to the variation in Gamma 2 caused by the discrepancy in the asymmetry between the left and right arms for the 2.5T 2254 MeV data, and that the total errorbar (statistical+systematic) is about 33% of the value of the moment, while the discrepancy causes a 20% change, for comparison. Also discovered that Toby's rootfile code appears to produce root files formatted differently from the ones his packing fraction script calls so working on eliminating the differences so that they can actually run together.

03/29/2018

Present: Karl, David Feature Presentations :

• David

Presented an update on the 2.5T 2254 MeV data asymmetry comparison, showing the result of replaying the data with a tighter momentum cut. Unfortunately, the tighter momentum cut seems to worsen the chi^2 comparison rather than improve it. Also showed and discussed with Karl an attempt to determine how serious the effects of the asymmetry discrepancy are on the final value for Gamma 2. The discrepancy seems to be responsible for a 20% variation in Gamma 2, but Karl said this value should be compared to the size of the existing error bar to determine if just throwing a systematic on and using the original data would be a valid way to go. Also re-showed the comparison of data taken on the first sweep up the momentum spectrum to data taken going back down, and showed that the largest discrepancy only occurs on the second set of runs, though no glaring change is notable in the log book.

David also mentioned that he's started work on trying to replay Toby's root files to re-generate the packing fractions for the 2.5T data.

Verbal Updates:

None

03/23/2018

Present: Chao, David Feature Presentations :

• Chao

Trying to resolve the issue Ryan discovered with acceptance not being continuous for production runs, using Dummy run to try and look at background and subtract out the effects of the target cell itself, runs are scaled by live charge so are proportional to cross section, so can be subtracted. This subtraction removes everything outside the target cell, effectively, the background, but does not consider the difference between foil target and extended target. Cut simulated target into 1mm slices to investigate-- for real target, there is no cross section difference between z=0, z=-13, and z=13, for any kinematic variable. Chao's conclusion is that either simulation doesn't match well, *or* the acceptance should not be dependent on the z position in the target. See slides attached to agendas section.

Verbal Updates:

• David

Left arm replay finished and asymmetries regenerated for 2.5T 2.2GeV runs, ran into issue with many of the right arm runs failing repeatedly on the batch farm. Going to try running interactively with Screen and using a different queue to avoid timeouts.

03/09/2018

Present: Ryan, J.P., Karl, David Feature Presentations :

None.

Verbal Updates:

• Ryan

Still waiting on Chao to get back to him about cross section issue, said Chao's explanation makes sense to him. J.P. asked about question dealing with the Y acceptance, but Ryan commented that he hasn't talked to Chao about it yet. Ryan agrees that the target length is the only thing different between carbon and production runs and that this is likely the source of the cross section issue.

• David

Replay finally working, ran into issue with some of the files coming out un-filled from the batch farm, but this is an issue Ryan has seen before and Ryan advised that he replay just the failed runs repeatedly until all of them function.

11/27/2017

Present: Ryan, Ellie, J.P., Karl, David Feature Presentations :

None.

Verbal Updates:

• Ryan

Discussed progress on the PRL with Karl and J.P., and whether or not the acceptance should be included.

11/17/2017

Present: Ryan, Ellie, J.P., Karl, David Feature Presentations :

None.

Verbal Updates:

• Ryan

Corresponding about Hyperfine results with Franziska Hagelstein, got numbers for delta_1 and delta_2, Karl suggested that this is good but evidence that since Ryan's data is on the Arxiv, people are going to want to use it and this is more incentive for us to be expedient in getting to publish. Ryan is working on finishing the hyperfine paper and intends to include both 2.2 GeV 2.5 T data, and the g1 point.

• Karl

Has approved Toby's thesis, after edits that provide more detail on the choice of the ratio method over the fit method for the packing fractions.

• David

Still working on tight dp cut replay, has all of Toby's dilution and packing fraction scripts running locally, Ryan and Karl suggested trying to replay dilutions with a tighter acceptance.

• Chao

Trying to get acceptance study running on JLab batch farm. Longitudinal study for the acceptance is done.

10/27/2017

Present: Ryan, Ellie, J.P., David Feature Presentations :

• Chao

Acceptance study for the longitudinal settings is just about finished. Elastic peak agrees well with theory, continuity of nu spectrum is good. Needs a conversion between slow and fast raster current. Transverse spectrum has not as good continuity, will be fixed soon.

Verbal Updates:

• David

Still working on tight dp cut replay, showed proof of principle doing dp cut on bin by bin basis, that seems to give more evidence that this is the issue, but aims to make it better with the count by count replay.

• Karl

Showed plots of g2p packing fractions vs SANE packing fractions, discussed the elastic fit method with Toby to determine that the .3 packing fraction is not good, but wants to investigate the suspiciously high 2.5T packing fractions, since SANE data never goes above .74.

10/06/2017

Present: Ryan, Ellie, J.P., David Feature Presentations :

None

Verbal Updates:

• Ryan

Working on the PRL for the ChiPT paper, just started.

• David

Working on resolving systematic shift in 467 Nu point for 2.2 GeV 2.5T asymmetry between left and right HRS, showed normalized yields, J.P. and Ryan suggested a tight dp cut. Also discussed the suspiciously good chi^2 generated with the method J.P. suggested before, J.P. said he thinks it is fine that the chi^2 is small but that it is necessary to evolve the kinematics of one arm to the other one before combining the 2.5T asymmetries. Also mentioned working on a cross check for the 5T data for g2 with Toby and Ryan, but has a sign error, it was suggested for David to fix the sign of the asymmetry to the theory or the elastic asymmetry peak.

09/22/2017

Present: Ryan, Chao, Ellie, Karl, David

Feature Presentations :

None

Verbal Updates:

• Ryan

Sent model codes to David, discussed dilution's odd behavior at nu > 1000 MeV, explained that previously he and Toby have switched to a model above 950 MeV abruptly from data. Said that packing fraction systematic error doubled after Toby fixed the radiative correction issue. Karl and Ryan discussed the issue of Toby assuming the ratio of carbon to nitrogen was a flat 15%, where Ryan was able to find a paper plotting it vs W.

• Chao

Unable to speak, but will present 5T 2.2 GeV acceptance next week.

• David

Has generated g2 for 2.5T 2.2GeV data, will refine over the coming week.

09/06/2017

Present: Karl, J.P., David, Ellie

Feature Presentations :

• David

Showed a study on the left and right arm HRS asymmetry comparison for 2.5T. Was able to replicate Ryan's results for 5T asymmetries, J.P. and Karl suggested redefining the chi^2 in terms of the uncertainty of both arms to remove ambiguity. 2.5T 2.2 GeV asymmetries show good agreement with the exception of three data points, which David is investigating, after noting that the runs going into those data points jump by about 5 days and change target material. Karl and J.P. suggested it was also important to obtain information about whether Toby's dilutions should change based on the target material. More details on his slides can be found here.

Verbal Updates:

None

08/23/2017

Present: Ryan, J.P., Toby, David, Alexandre

Feature Presentation :

None

Verbal Updates:

• Ryan

Discovered the the divergence in XS from Toby was because the radiation lengths were flipped in Toby's analysis-- TA comes after TB (T after and T before). Toby promised to re-run the code and ensure

• David

Working on Left+Right HRS 2.5T comparison still, trying to get Chi^2 for 5T comparison to be as good as in Ryan's analysis. Using same runs, LHRS asymmetry agrees with Ryan's but RHRS differs for three data points.

08/09/2017

Present: Ryan, Chao, J.P., Karl, David

Feature Presentation :

None

Verbal Updates:

• Chao

Working on optics runs to complete acceptance study, trying to figure out a way to work around not having definitive BPM Results.

• Ryan

Trying to get signatures from committee on thesis, still waiting to hear back from Toby about dilution issues.

• David

Working on Left+Right HRS 2.5T comparison, have preliminary results but with a very large Chi^2 of ~25, trying to work on account for second order effects to knock that down and make sure it is viable to combine the data from both arms.

08/02/2017

Present: Ryan, Karl, David, J.P.

Feature Presentation :

None

Verbal Updates:

• David

Still working on HRS asymmetry comparison for the LHRS and RHRS, installing ROOT and configuring local coding environment. Ryan agreed to help guide David through setting up his environment.

Discussed intelligent magnet power supply, which David will investigate communicating with via USB, irrelevant to the g2p collaboration.

• Ryan

Thesis edits essentially complete, L+R HRS Comparison had an angle difference of .3 degrees Ryan and Karl discussed trying to get a better dilution and packing fraction from Toby to deal with other issues in 2.5 T 2.2 GeV data Ryan should be able to get shell of Hyperfine results soon

• Karl

Karl asked Xiaochao to contact Jie about finishing the BPM analysis, Jie responded that he will not finish the analysis. In terms of administrative issues, Karl agreed to add David to g2p mailing list so that he can take over sending out weekly meeting emails from Ryan.

07/19/2017

Present: Ryan, Toby, Karl, David

Feature Presentations :

• Toby

Showed an update on the dilution and packing fraction calculation for 2.5T. This is an issue at large nu where the fit to the packing fraction and dilution grow large where the model expects them to level off. Toby thinks this might be an issue with the radiative scale factor he is applying to the data. There is also some questions about the choice of acceptance cut used to generate the quantities. He chose a large acceptance cut to improve statistics but this might have systematic effects causing the rise. He will repeat the analysis at a few difference acceptance cuts to check this effect. More details on his slides can be found here.

Verbal Updates:

• David

Working on HRS asymmetry comparison for the LHRS and RHRS

07/12/2017

Present: Ryan, Toby, Karl, Ellie, David, Chao

Feature Presentations :

• Ryan

Showed beam energy values for the experiment run period on production runs. There are some bigger than expected fluctuations. To first order the effect of this is small (Mott XS variation) but the question is how this could effect calibrations, such as the BPM calibration. More details on his slides can be found here.

Verbal Updates:

• Toby

2.5 T packing fraction values. Taking into account yield drifts gives a systematic error on the order of 15% at 2.2 GeV 2.5 T. Looking into 1.7 GeV settings next

• David

Working on HRS asymmetry comparison for the LHRS and RHRS

• Chao

Working on acceptance simulation. Running simulation for the production runs. Slow going because he can only runs a handful of jobs at a time.

07/05/2017

Present: Ryan, Karl, Toby, J.P., Chao, David

General Discussion:

• Batch farm is prioritizing multi-threaded jobs so this will impact g2p replay and also Chao's acceptance simulation timeline.

• Toby is going to start looking at the 2.5T dilutions this week.

• David has generated asymmetries but results are consistent with zero so he will try larger binning (up from 10 MeV)

06/28/2017

Present: Ryan, Toby, David, Karl, Chao, JP, Alexandre, Xiaochao, Ellie

General Discussion:

• 2.5T data quality. Based upon error bars from a quick moment analysis of the 2.5T data from Ryan it appears that the 2.2/1.7 GeV data is useful for publication with Q2 values of approx 0.04 GeV2 and 0.02 GeV2, respectively. The 1.1 GeV data error bars are very large, which is in part due to the very small asymmetry prediction at that low Q2 (0.009 GeV2).

• Toby is leaving to start a job on July 24. He will try and get something together for the dilution and packing fraction analysis for the 2.5T settings.

• Chao is making good progress with the longitudinal acceptance for the carbon data. He is able to produce a continuous spectrum with good agreement in the overlap regions at large nu. Unfortunately there is no overlap around the delta-resonance. He will do a similar study except at the transverse settings next.

• David is going to work on the data quality check for the 2.5T asymmetries. His first step is to produce g2p asymmetries and compare to results from Ryan and Toby.

06/21/2017

No meeting because of Hall A collaboration meeting.

06/14/2017

Present: Ryan, Karl, Toby, J.P.,Chao

Feature Presentation :

• Ryan

Showed the results of a quick analysis of the 1.7 and 1.1 GeV 2.5 T settings. The 1.7 GeV data looks pretty good and can most likely be used going forward. There is one momentum setting just previous to the delta where the majority of the data was taken with a mismatched septa and dipole configuration, so it is not included in these slides. He will try including this data to see the effect it has on the results. It should probably be OK for the asymmetry. The 1.1 GeV data looks worse statistically, which related to the much smaller asymmetry that we see as we go to lower and lower Q2. As we go to lower Q2 we also have the added complication of the Christy fit we're using for the unpol XS getting worse and worse. Going forward Ryan will do a quick moment analysis of this data. More details on his slides can be found here.

• Toby

Showed different methods for calculating the low-x portion of the BC sum rule. These include the polarized PDF's and Hall B model. The problem is that none of these methods are really applicable at the g2p kinematics (PDF's hold down to Q2 = 1 GeV2), and that the low-x portion of the integral must be a sizable contribution for the BC sum rule to hold. Going forward we will most likely assume that the BC sum rule holds and use that assumption to place a limit on the low-x behavior of g2 at low Q2. More details on his slides can be found here.

06/07/2017

Present: Ryan, Karl, Toby, J.P.,Chao, Ellie

Feature Presentation :

• Ryan

Showed the results of a quick analysis of the 2.2 GeV 2.5 T settings. The goal of this analysis was to check the overall quality of the data and includes the combined statistics of both the RHRS and LHRS. The overall statistical precision of the data is pretty good considering the much lower target polarization of the 2.5T settings (15% on average compared to the 70% for the 5T runs). Going forward he will do a similar study for the 1.1 GeV and 1.7 GeV settings and also complete a very preliminary moment analysis of these settings. These settings also need a completed dilution and packing fraction analysis slides.

Verbal Updates:

• Jie

Published his BPM tech-note update to the wiki.

• Chao

Summarized his acceptance study progress. So far he has applied his 8mm raster cut method (+/- 15mrad in ph and 20 mrad in th) to the elastic carbon long. setting and gets 5% agreement between the simulation and data. He is able to drastically reduce the uncertainty in the raster cut by cutting on current and not size. The timing information of the raster is known very well. He knowns the time the raster spends inside the area of the cut and the time it spends outside. The ratio between these two times is scaled to the total charge. He is currently applying this to all the carbon dilution data at longitudinal to see how this procedure works at other P0. He estimates this will take 2-3 weeks. After that he will move onto the transverse setting and estimates that will take an additional 1-2 months to complete.

05/31/2017

Present: Ryan, Karl, Toby, J.P.,Chao

Feature Presentation :

• Toby

Showed an update on his g2 moment calculations. His moments included the BC sum rule and also DeltaLT. From his analysis it was concluded that it is very difficult to verify the BC sum rule at low Q2 because of the lack of data at low x. The DeltaLT results look much better. More details on his slides are found here.

Verbal Updates:

• Jie

Still working on his BPM tech-note/update.

• Chao

Planning on talking with JP about his acceptance study update. Had to leave early to go to another meeting.

05/24/2017

Present: Ryan, David, Karl, Toby, J.P., Jie, Ellie

Feature Presentation :

None

Verbal Updates:

• Jie

Still working on his BPM tech-note/update. Hopes to have it done by next week. This might also be his last g2p meeting before he starts his new job. Will also add his thesis to the wiki.

05/17/2017

Present: Ryan, David, Karl, Toby, J.P. Chao

Feature Presentation :

• Ryan

Showed an analysis for an explanation for why the 2.2 GeV Longitudinal polarized DS does not go to zero below the pion production threshold after tail subtraction. His idea is that the elastic radiative events come from a different part of the acceptance than the inelastic events. This effect could be potentially large if a large acceptance cut is used. The big unknown in this analysis is what is the exact angle difference. With the current reconstruction/simulation status it's very difficult to determine. In the future, if the simulation is able to reproduce the angular acceptance then the tails can be calculated and weighted for the simulated acceptance. This also raises potential problems for getting a polarized DS from an asymmetry and cross section calculated with different acceptance cuts. For now, the analysis will proceed with the old method and assume one scattering angle. Ryan will check the results of using a tight asymmetry and tight cross section cut to see how the tail subtraction is effected. More details on his slides are found here.

• Chao

Showed an update on the optics simulation and he is currently trying to beat down the systematic error from making a raster cut. He is currently cutting on raster current as opposed to raster size to improve the uncertainty. With a raster cut the simulation is much better able to reproduce the data.

05/10/2017

Present: Ryan, Jie, David, Toby, Ellie, JP

Feature Presentation :

• Ryan

Showed an analysis update of the results section of his thesis and includes analysis of all of the 5T settings. He evaluated the g1 moments and the hyperfine splitting contributions for g1 and g2. More details on his slides are found here.

05/03/2017

Present: Ryan, Jie, David, Karl, Toby, Ellie, JP, Chao

Feature Presentation :

• David

Showed an update for calculating the acceptance correction by normalizing to the elastic cross section. His uncertainty in this method is slightly better than the results Toby showed before and his dominant uncertainty is the scattering angle reconstruction and it's effect on the Mott XS and elastic form factors. He will look into further separating the quasi-elastic and elastic peaks by subtracting out the elastic tail for helium-4. More details on his slides are found here.

4/26/2017

Present: Ryan, Jie, David, Karl, Toby, Ellie

Feature Presentation :

• Ryan

Showed results of a parallel asymmetry analysis between Toby and Ryan. The asymmetries agree very well and the only slight difference is at the longitudinal setting. This difference is a result of slightly different acceptance cuts used in the analysis and goes away if the same cuts are used. More details on his slides are found here.

• Toby

Posted an update on last weeks slides to include a model comparison to his calculated cross sections. His slides are found here.

4/19/2017

Present: Ryan, Jie, David, Karl, Toby, Ellie, Chao

Feature Presentations :

• Toby

Showed a comparison between calculating polarized cross sections using a model and using data. In the data method he multiplies the raw asymmetry by the raw cross section with no dilution correction. In the model method he applies the dilution to the asymmetry and then uses a unpolarized proton model (radiated). The two results agree pretty well except for the 3.3 GeV setting where the yield drifts present problems with the dilution and cross section calculation. We will most likely have to use a model at this setting. More details on his slides are found here.

Verbal Updates:

• Chao

Talked about using the raster cut in the simulation to match data and simulation for the acceptance. He's going to soon try and apply this raster cut method across the momentum settings at the longitudinal setting and see how well the simulation can match data. He's currently using a 30 mRad phi cut, which is significantly larger than the cut Toby is using and will the systematic uncertainty from knowing the cut boundary. There is going to be an additional systematic from using a raster cut when it comes to calculating the accumulated charge. He is looking into this.

4/12/2017

Present: Ryan, Jie, David, Karl, Toby, JP, Ellie

No presentations this week. Toby and Ryan are working on comparing their asymmetry results to confirm that their methods agree. Jie's graduation date is May 9 and he is still working on finishing up his thesis.

3/29/2017

Present: Ryan, Jie, David, Karl, Toby, JP, Chao, Ellie

Feature Presentations :

• Ryan

Showed an update including the Gamma1 and GDH moment calculations. The results have very good statistical error bars when compared with the Hall B data and also his integration of the Hall B data agrees with the published Hall B results. More details can be found in his slides here.

• Chao

Showed an update on the simulation for Run 5612. He is able to reproduce the edges of the acceptance better if he places a very tight cut on the raster size. This suggests a beam position reconstruction issue. Going forward he is going to look at the uncertainty introduced by this raster cut and see which has the larger contribution to the uncertainty: raster cut or acceptance cut. More details can be found in his slides here.

3/22/2017

Present: Ryan, Jie, David, Karl, Toby, JP, Chao

Feature Presentations :

• Ryan

Showed a comparison between the Bosted model and low Q2 SLAC data. The agreement between data and the model is better at larger Q2 and around 15% at the 5T setting kinematics. Ryan is waiting on an updated model from Eric Christy that includes the low Q2 data in the fit. More details can be found in his slides here.

• Toby

Also showed a comparison between the Bosted model and the SLAC data but included a preliminary g2p cross section as well. The agreement is at the 15% level with our data. More details can be found in his slides here.

• David

Showed a method for calculating the helium-4 elastic cross section from g2p empty dilution runs. He compares the g2p data to the Rosenbluth result from the MSW (McCarthy-Sick-Whitney) form factors and get's agreement at the 10% level. He will look into adding systematic uncertainty estimates to both his measured and calculated quantities. He will also investigate the 'Delta E' term in the elastic peak radiative corrections. More details on his slides can be found here.

Verbal Updates:

A request was made by Eva-Maria Kabuss for some g2p slides to present at DIS 2017 (April 3-7).

3/15/2017

Present: Ryan, Jie, David, Karl, Toby, JP, Chao, Ellie

Feature Presentations :

• Chao

Showed an update on the optics and acceptance simulation. He showed that for a carbon run with no liquid helium and at the longitudinal target configuration he is able to match data to simulation with a very tight acceptance cut. He is working on expanding this cut to reduce the overall systematic uncertainty in the acceptance. Super elastic events and carbon excited states make expanding this range difficult. More details on his slides can be found here.

Verbal Updates:

• Jie

Graduation date is set for May 9, 2017.

3/8/2017

Present: Ryan, Jie, David, Karl, Toby, JP

Feature Presentations :

• Ryan

Showed an update on how he is extracting g1 from the longitudinal data and evolving it to a constant Q2. He also showed a preliminary calculation of the gamma0 moment, which agrees well with the current Hall B measurements and chiral perturbation theory predictions. More details on his slides can be found here.

3/1/2017

Present: Ryan, Toby, David, Jie, JP, Karl, Ellie, Chao

Feature Presentations :

• Ryan

Showed an update on the systematic error analysis going into the asymmetries, polarized cross sections and radiative corrections. Currently the dominating systematic error is from the angle reconstruction and use of an unpolarized model to create the polarized cross sections. The angle reconstruction error is amplified at low angles because of the strong Mott dependence. The unpolarized cross section systematic could be reduced in the future by substituting in g2p data for that component. More details on his slides can be found here.

• Jie

Gave an update on the BPM calibration process. Showed that there is a strong position dependence to the off-sets determined from Harp scans. Through the reconstruction procedure he is unable to reproduce the location of the harp scan points because of this position dependence. More details on his slides can be found here.

• Toby

Presented the status of the dilution analysis for the 3.3GeV settings. The analysis is complicated by the large yield drifts seen in the data. He is still trying to figure out a method to give reasonable dilution results at this setting. But whatever method he settles on will most likely come with an increased level of systematic error. More details on his slides can be found here.

2/22/2017

Present: Ryan, Toby, David, Jie, JP

Feature Presentations :

No feature presentations this week. Everyone is planning on presenting next week.

2/15/2017

Present: Ryan, Toby, David, Jie, JP

Feature Presentations :

• Jie:

Showed an update the BPM calibration. There was some discussion on the base assumptions Jie is making in removing potential position dependence on some calibrations constants (b-/b+). More details on his slides can be found here.

General Discussion :

• Toby:

Updated target polarizations are available now.

• Ryan:

HERMES publication from 2013 of new BC Sum Rule calculation at Q2 = 5 GeV2. Data is consistent with 0 but with large error bars.

2/8/2017

Present: Ryan, Toby, David Karl, Jie, JP, Chao, Ellie

Feature Presentations :

• Ryan:

Showed the final systematics for the inelastic and elastic RC's. The end result is 2-3% for the elastic tail and 3-5% for the inelastic RCs. More details on his slides can be found here.

General Discussion :

• Toby:

Updating his systematic uncertainty on the target polarization analysis.

2/1/2017

Present: Ryan, Toby, David Karl, Jie, JP, Chao, Ellie

Feature Presentations :

• Jie:

Gave an update on the BPM analysis. Still have trouble solving the position jumps. More details on his slides can be found here.

• Ryan:

Showed the outline of the g2p radiative corrections procedure, including the polarized elastic tail and RADCOR and POLRAD formulations of the inelastic RCs. Also presented systematics for the unfolding procedure. He will next finalize the theory systematics for the RCs. More details on his slides can be found here.

• Chao:

Gave an update on the acceptance study. He showed that at the longitudinal setting the shift from 0 in the theta_tg histogram is caused by the target field. The effect is more pronounced at transverse settings. More details on his slides can be found here.

General Discussion :

• Toby:

g2p dilutions are now available on the wiki.

1/18/2017

Present: Ryan, Toby, Karl, Jie, JP, Chao, Ellie

Feature Presentations :

• Jie:

Hoping for a May graduation with his thesis split between three topics (g2p is one). Point was made that Jie must finish his BPM study before graduation because at this point he is the only one that can do it. More details on his slides can be found here.

• Toby:

Hoping for a May graduation with a close-to-final g2 his goal for his thesis. Finishing up the dilution analysis for 3.3 GeV 5T. More details on his slides can be found here.

• Ryan:

Hoping for a June-August graduation with a close-to-final g2/hyperfine point his goal for his thesis. Finishing up the g2p radiative corrections procedure setup. More details on his slides can be found here.

• Chao:

Gave an update on the acceptance study. He is still having a hard time matching the simulation to data. More details on his slides can be found here.

General Discussion :

• Karl:

is looking into the EG1b data for our highest Q2 settings as the parallel component for g2.

1/11/2017

Present: Ryan, Toby, Karl, Jie, David, Chao

Feature Presentations :

• Ryan:

Showed the effect a 0.3 degree scattering angle difference between HRSs would have on the data. Calculated this difference using models and then compared the data to it. The data is consistent with a straight line fit at 0, so the statistics of g2p are not sufficient to make a definitive statement. Also showed a calculation for the uncertainty in the out-of-plane polarization angle using a psuedo Monte-Carlo method. The uncertainty is around 1%. Details of his slides can be found here.

1/04/2017

Present: Ryan, Toby, Karl JP, Jie,

Feature Presentations :

• Ryan:

Showed an update on the comparison between the LHRS and RHRS asymmetries for 2.2GeV 5T transverse. Using course 70 MeV bins and cutting out runs with large livetime and charge asymmetry he was able to get good agreement between the two spectrometers. The agreement is independent of the out-of-plane polarization angle correction. There is some question about the effect of the minor difference in the scattering angle between HRS's and the asymmetry. He will present on this difference at the next meeting. More details on his slides can be found here.

• Jie:

Still looking into the BPM calibrations and the source of the BPM position jumps that don't see a corresponding yield change. He hopes to have this analysis wrapped up by the end of January. More details on his slides can be found here.

• Other news:

At the 1/18/2017 weekly meeting we're planning on having a discussion on the analysis path forward. The primary focus on this discussion will be the experimental cross sections.

12/21/2016

Present: Ryan, Toby, Karl, Vince, JP, Jie, Chao

Feature Presentations :

• Toby:

Showed an update on the packing fraction analysis with a new method that is similar to his dilution calculation. This method gives a lower uncertainty than his elastic fit method. His two methods agree within the uncertainties for almost all of the settings. He will check the few kinematic settings where this isn't true and also try to pin down the systematic error from using the Bosted model to scale C12 to N14. More details on his slides can be found here.

• Other news:

Vince's last day at g2p meetings. Good luck at your new job Vince!

12/14/2016

Present: Ryan, Toby, Karl, Vince, JP, Jie, Chao

Feature Presentations:

• Jie:

Showed a status update on the BPM calibration procedure. More details can be found in his slides here.

• Chao:

Still having trouble matching the width of the simulation peaks to peaks from data. Even getting rid of all apertures did not sufficiently widen the simulation peak. He is continuing to look into it. More details can be found here.

12/07/2016

Present: Ryan, Toby, Karl, Vince, JP, Jie, Alexandre

Verbal Updates:

• Toby

Working on getting his dilution code back up and running

• Ryan

Working on asymmetry comparisons between the LHRS/RHRS at 2.2 GeV 5T Transverse.

• Jie

Talking with Pengjia still about the BPM calculation procedure. Will give an in-depth update on the status of the BPM analysis at the next meeting.

11/30/2016

Present: Ryan, Toby, Karl, Ellie, JP, Jie, Kalyan, Alexandre, Vince, Jixie, Chao

Feature Presentations

• Ryan

Showed an update on the out-of-plane polarization angle calculation. The calculation agrees with Chao's result but still seems too large (40 - 65 degrees). Chao is working on confirming the results. Details of his slides can be found here.

• Toby

Showed an update on the packing fraction analysis. He presented final values for all settings except for 1.1 GeV 2.5 T. The difficulty at this setting is that the quasi-elastic peak is barely separable from the elastic peak so he is unsure of how to fit it. This is also a problem at the other 2.5 T settings and is manifest in the larger systematic uncertainties. Details of his slides can be found here.

Verbal Updates:

• Chao

working on out-of-plane polarization angle calculation and will also confirm the proton elastic simulation results for Toby.

• Jie

Talking with Pengjia still about the BPM calculation procedure.

11/23/2016

Present: Ryan, Karl, JP, Jie, Kalyan, Alexandre

• Jie

Discussed BPM calibration method

• Ryan

Working on calculating the out-of-plane polarization angle, with help from Chao. Hoping to confirm method with Chao and present something soon.

11/16/2016

Present: Ryan, Toby, Karl,Chao, Jie, Vince, Alexandre

Feature Presentations

• Jie

Showed an update on the BPM calibration procedure. His correlation method for calculating the pedestals improves the uncertainty but does not affect the position reconstruction. In the calibration procedure there is an offset term that as large variations between calibration points. Pengjia fit this constant for current dependence but it is also possible it might have some positional dependence. Jie is going to talk with Pengjia about this. More details on his slides can be found here.

Verbal Updates:

• Toby is working on finalizing the uncertainties for the packing fraction analysis and is running into some issues with g2psim.

• Ryan is working on calculating the out-of-plane polarization angle, with help from Chao.

11/02/2016

Present: Ryan, Toby, Karl, JP, Vince, Alexandre

Feature Presentations

• Ryan

Showed a brief update on calculating the out-of-plane angle correction to the perpendicular polarized cross sections. He will talk to Chao about how to make this calculation using the reconstructed variables in the replayed ROOT files. More details on his slides can be found here.

• Toby

Showed a slide on the yield spectra for the elastic runs in PF analysis at all kinematic settings. The nitrogen and helium peaks are only clearly visible at the 2.2 GeV 5T transverse setting, so he will need to adjust his fitting routine to account for this at the other settings. More details on his slides can be found here.

10/26/2016

Present: Ryan, Toby, Karl, Jie, JP, Chao, Ellie, Vince, Jixie

Feature Presentations

• Ryan

Showed an update on the polarized radiative corrections using POLRAD at the g2p kinematics (non-constant scattering angle). He showed that using the same angle fit for all the input spectra (as opposed to individual fits representing measured data) the systematic error was similar to that of data taken at a constant scattering angle. For this study he used the MAID 2007 model. He recommends using models for the RC'ing of g2p data but those models could be tuned and checked using measured data. More details on his slides can be found here.

Verbal Updates:

• Chao

Working on the optics and acceptance simulation and tuning the simulation aperatures. Showed a short slide with better agreement between data and simulation. Still working on improving this.

• Jie

Working on the BPM position calibration procedure.

10/19/2016

Present: Ryan, Toby, Karl, Jie, JP, Chao, Ellie, Vince, Jixie

Feature Presentations

• Toby

Showed an update on his method for calculating the packing fraction, along with his estimate for the systematic uncertainty. He's hoping to finalize the results for the 5.0 T settings within the next few weeks. More details on his slides can be found here. There was some discussion that his uncertainty of ~8% in the fitting method is overestimated as described in the slides, so hopefully the systematic uncertainty is at the 10% level, maximum.

Verbal Updates:

• Chao

Working on the optics and acceptance simulation and tuning the simulation aperatures.

• Jie

Working on the BPM position calibration procedure. Still trying to fully understand Pengjia's method.

• Ryan

Working on setting up inelastic radiative corrections procedure for changing angle of g2p.

10/12/2016

Present: Ryan, Toby, Karl, Jie, JP, Chao

Feature Presentations

• Jie

Showed final results for the BPM pedestal uncertainty using his new correlation method for the 2.2 GeV 5T transverse setting. The uncertainties are about a factor of 3-4 better than previous and are approx. 1mm and 1mrad at the target. He is moving on to finishing this study at other settings and also looking into the BPM calibration procedure and beam position jumps. More details on his slides can be found here.

Verbal Updates:

• Chao

Working on the optics and acceptance simulation. Believes that the previous mismatch he showed with data and simulation at bigger angular acceptance was due to the simulation aperatures blocking more events than seen in the data. Current size estimates of the aperatures is from a combination of g2p survey and historical Hall A information.

• Toby

Working on packing fraction results and updating the systematic error analysis. Hoping to finalize shortly.

• Ryan

Working on setting up inelastic radiative corrections procedure for changing angle of g2p.

10/05/2016

Present: Ryan, Toby, Karl, Ellie, Jie, JP, Jixie

Feature Presentations

• Ryan

Showed the reconstructed angle for a loose cut on all of the LHRS g2p production data. The fit is a combination of a linear and exponential fit; this form is suggested from a Jixie ELOG post. For the most part there is good agreement with the data to the fit, and outliers from the fit is a potential criteria for selection of good runs. He used these fits to mimic g2p data and test RC procedures on data at different angles. He found that he could do RC's with small systematic error if he used the same fit for all input spectra. This is not the case for g2p data, so he's working on improving the method. More details on his slides can be found here.

Verbal Updates:

• Jie

Working on the BPM pedestal issue. He's now considering correlations between all channels in the BPM pedestals. This slightly increases his uncertainty but it is still smaller than Pengjia's result and helps alleviate the triple peak issue.

• Toby

Working on packing fraction results and updating the simulation calculations needed for the cross section ratio input.

• SPIN 2016

Chi-PT calculations of the polarizabilities are still bad. NEED DATA!

9/21/2016

Present: Ryan, Toby, Karl, Chao, Jie, JP, Jixie, Kalyan, Vince

Feature Presentations

• Jie

Showed an update on the BPM pedestal calculation. Found a correlation between the pedestals on BPM channels. By using a rotated coordinate system, he can decouple the correlation. This allows for a reduced uncertainty in the BPM pedestal uncertainty contribution to the BPM calculation. More details on his slides can be found here. Will work on finalizing the updating uncertainty calculations and continue with checking the BPM calibration.

• Ryan

Showed the reconstructed angles for three different asymmetry cuts for both the transverse longitudinal asymmetries. There is a difference between the hot-spot angle in the transverse asymmetry. The RHRS accepts smaller angles in the transverse configuration but this cannot account for the difference in the HRS asymmetries between L/R. More details on his slides can be found here. He will try different cuts on different variables to try and find a set that gives agreement between the LHRS/RHRS.

• • NO MEETING NEXT WEEK BECAUSE OF SPIN 2016

9/14/2016

Present: Ryan, Toby, Ellie, Karl, David, Chao, Jie, JP, Jixie, Kalyan, Vince

Feature Presentations

• David

Showed a statistical analysis between the LHRS and RHRS asymmetries for the 2.2GeV 5T transverse/longitudinal data. Concluded that for long. data the two spectrometers are statistically measuring the same thing. Further work still needs to be done on for the transverse asymmetries. His slides can be found here.

• Toby

Showed an updated packing fraction calculation where he replaces fits to the quasi-elastic and quasi-elastic contamination with the Bosted model. His packing fractions are in much better agreement with this method and the consensus is that the fit method was driving the large differences previously seen. He was given suggestions on trying to better quantify the quasi-elastic contamination, including using other models and separating the kinematic regions using acceptance cuts. More details can be found in his slides here.

• Jie

While on the schedule, he will present next week.

9/7/2016

Present: Ryan, Toby, Ellie, Karl, Chao, Jie, JP

Feature Presentations

• Chao

Gave an update on the acceptance study of the 5T longitudinal setting. He's currently working on tuning the resolution of the simulation package. He finds that he can match the width of the elastic peak for a small range in theta and phi target but as he increases that range his simulation produces too narrow of a spectra. He is working on fixing this issue. His slides can be found here.

• Ryan

Showed a comparison between the 5T longitudinal asymmetries using different acceptance cuts. He demonstrated that within our statistical error bars we do not need to make a bin-centering correction to the asymmetries for the longitudinal setting. He also tried to see if a model accurately described the asymmetry change with angle but was not successful. More details can be found in his slides here.

8/31/2016

Present: Ryan, Toby, Ellie, Karl, Jixie, Vince, Jie, Alexandre, JP

Feature Presentations

• Jie

Gave an update on the BPM pedestal analysis. He showed results from the pedestal analysis of beam trip runs for both the Happex DAQ and HRS DAQ. HRS DAQ has cleaner pedestals but the HRS DAQ is less precise. The pedestal shift seen in the HAPPEX DAQ is continuos with time. He will continue to look at the BPM calibration procedure and try and quantify the effect the pedestals have on the BPM uncertainty. More details can be found in his slides here.

Verbal Updates:

• Ryan

Continuing to look at HRS asymmetry angle dependence

8/24/2016

Present: Ryan, Toby, Ellie, Chao, Vince, Jie, Alexandre, JP

Feature Presentations

• Toby

Showed an update on the packing fraction analysis. He has been able to successfully fit the two elastic peaks (N2 and He4) and quasi-elastic peak to produce packing fraction results. He also presented an alternative calculation to the packing fraction, just using the helium peak from production and a dummy/empty run. His two methods agree at the ~10% level but differ greatly from what Melissa showed previously. Toby will continue to look at his fits and see if there is room for improvement there because there is some fit dependence on the result. One suggestion was to fit the simpler dummy run He4 elastic peak and use those fit parameters in the production runs. More details can be found in his slides here.

Verbal Updates:

• Ryan

Continuing to look at HRS asymmetry angle dependence

• Jie

Working on understanding Pengjia's BPM code.

8/17/2016

Present: Ryan, Toby, Ellie, Chao, Vince, Jie, Alexandre

Feature Presentations

• Ryan

Showed a comparison between asymmetries between LHRS and RHRS for the three 5T settings: 2.2 GeV long/trans and 3.3 trans. Overall there is good agreement between the HRS's, and the biggest disagreement is between the arms at the 2.2 GeV trans setting. Ryan will check that scattering angle dependence of the asymmetries next to see if this can improve the agreement. Currently the RHRS scattering angle reconstruction is not correct. Chao believes this is a coordinate system issue in his code. Slides can be found here.

Verbal Updates:

• Chao

Back at JLab for one year. First thing he will focus on is correcting the scattering angle reconstruction for the RHRS replay. After this he will move onto the acceptance study for the 5T longitudinal setting.

• Jie

Working on understanding Pengjia's BPM code.

• Toby

Working on updating the target polarizations for the HRS's. Found a bug in his code in converting UNIX times. Also developing two parallel methods to determine packing fraction, one using fits and another using simulation.

8/03/2016

Present: Ryan, Toby, Karl, Vince, Jie, Alexandre

No Presentations.

Verbal Updates:

• Jie

Got code for BPM calibration from Pengjia. Still waiting on some further explanation from Pengjia on the code. He will focus on the 5T settings first in the calibration

• Toby

Working on the g2psim package and using it for calculating the packing fraction. Replayed RHRS 5T transverse data, and according to Chao it should have final optics.

• Ryan

Has a working model dilution code.

7/27/2016

Present: Ryan, Toby, Jie, Vince, Kalyan, JP, Karl

Feature Presentations:

• Jie

Working on trying separate two peaks in the BPM pedestal runs. It does not appear that the two peaks can be filtered based upon the frequency using an FFT. Moving forward he will check how the double peaks affect BPM calibration uncertainty and check the BPM calibration procedure. More details can be found in his slides here

• Ryan

Presented raw asymmetries with three difference acceptance cuts to highlight the angle dependence on the asymmetry in the delta-region. Was able to produce a similar trend in models using scattering angles from the data. Going forward will try to find acceptance cuts that select similar numbers of events and see if the ratio between data points is the same as the ratio of model points to do a bin-centering type correction. More details can be found in his slides here

7/20/2016

Present: Ryan, Toby, Jie, Vince, Alexandre , Kalyan, Karl, Ellie

Verbal Updates:

• Jie

Looking into 2-peak pedestal issue for the BPMs. Checking to see if the two peaks are at different frequencies and can be separated. If they cannot then the 2-peak pedestals will increase the BPM reconstruction uncertainty at the target to ~3-4mm (from 1-2mm) for runs with the double peak. Previously Pengjia did not consider any RMS value above 2000 in his analysis.

• Toby

Still working on getting the g2p simulation package to match g2p data. Able to now produce elastic peaks in the correct locations to match data. Requesting that someone familiar with g2psim make a post on the wiki detailing the variables in the output of the simulation root tree because they are not straight-forward to understand.

• Ryan

Completed setting up a python version of the radiated model code. Uses MAID/Hall B for the polarized and Bosted for the unpolarized. Does the unpolarized and polarized elastic tail but only uses RADCOR for the inelastic radiating.

7/13/2016

Present: Ryan, Toby, Jie, Vince, Alexandre , JP, Karl, Ellie

Feature Presentations:

• Jie

Showed a comparison between the BPM pedestals calculated during dedicated pedestal runs and during beam trips. The two methods agree, so Jie is moving forward with the beam trip method to fill in gaps for BPM pedestal calculations. His next step is to move onto checking the BPM calibration. More details can be found in his slides here

Verbal Updates:

• Toby

Still working on getting the g2p simulation package to match g2p data. This will be used for calculating the packing fraction

• Ryan

Working on producing radiated models to compare to the g2p data.

7/6/2016

Present: Ryan, Jie, Kalyan, JP, Karl, Ellie

Verbal Updates:

• Jie

Working on comparing pedestal values from dedicated pedestal runs and from beam-trip's. He's mostly found agreement and is working to settle the few outliers. After this he is moving onto to checking the BPM calibration.

• Ryan

Working on setting up radiated models to compare with the radiated data asymmetries.

6/29/2016

Present: Ryan, Toby, Jie, Vince, Kalyan, JP, Karl, Ellie

Feature Presentations:

• Jie

Gave an update on the BPM pedestal issues. In his slides he shows the pedestal histograms to demonstrate that the pedestal value is really shifting with time. Some pedestal's also exhibit a multi-peak structure, which ultimately will effect the uncertainty of the BPM calibration. He also showed the effect of using different BPM pedestal values for different runs and effects the BPM reconstruction. The resulting BPM position change is much larger than simulation would predict indicating that again that the BPM pedestal value is really changing with time. Going forward he will look to determine an accurate BPM uncertainty from the fluctuating pedestal values. More details on his slides can be seen here.

Verbal Updates:

• Toby

Working on updating Melissa's packing fraction code to use simulation to match the quasi-elastic peak, instead of relying on fits because the packing fraction result is highly-sensitive to the fit parameters.

• Ryan

Working on raw asymmetries and comparing them with Toby to make sure they agree.

• Vince

Has updated ChiPT calculations that he will send out over the mailing list.

6/22/2016

Present: Alex, Ryan, Toby, Jie, Vince, Kalyan

Feature Presentations:

• Toby

Received Melissa's packing fraction code. Found that there is now a difference in the nu histograms for the elastic runs when compared to what Melissa used in her analysis. Melissa's tech-note shows only a single elastic peak, but new root-files have both a elastic nitrogen and helium peak. The two peaks are separated by about 5 MeV at E0 = 2.2 GeV. The existence of an additional peak effects the applicability of Melissa's fitting routines to these new root-files. Toby will contact Melissa and see what she can provide. Slides are here.

Verbal Updates:

• Jie

Jie is still talking with Pengjia over the BPM pedestal issue. He hopes to have slides for next week's meeting.

• Ryan

Ed Folts confirmed the presence of helium bags in the septum bores and local dump box. In contact with Jessie Butler to find Ed's old pictures of the g2p target platform. Assuming helium is present in radiation thicknesses after scattering. Will update if there is any change. Tech-note with the radiation lengths can be found here

6/15/2016

Present: JP, Karl, Alex, Ryan, Toby, Chao, Jie, Vince, Ellie, Xiaochao, Kalyan

No presentations. Just verbal updated

• Jie

Jie gave a little more detail on the carbon cover from last week's slides. The carbon cover is a porous carbon sponge added to the BPM to help with radiation. This in itself shouldn't effect the pedestal but opening up the BPM to install it could have an effect. It's possible the pedestal change is also related to configuration changes in the target magnetic field. Jie will show more at meeting next week.

• Ryan

Confirmed from Chao that DP is not corrected for ELOSS. Still waiting to hear back from Ed Folts on g2p helium bags.

• Toby

Getting Melissa's packing fraction code this week. Will use it to update packing fraction calculations.

6/8/2016

Present: JP, Karl, Alex, Ryan, Toby, Chao, Jie, Vince, Ellie

Feature Presentations:

• Ryan

Gave an update on the radiation length calculation. He checked the energy loss calculation people did before and found out that we did not use the He bag during the experiment but before people built the He bag in the simulation. However the difference between He and air should not cause serious problem for us. More details can be seen in his slides here.

• Jie

Gave an update on the beam position problem. He worked together with Pengjia on this problem. The bpm database is updated so that the beam current dependence of the BPM is removed. Another problem is that the reported beam position would jump suddenly within the same momentum setting. Pengjia and he guess the pedestal of the BPM might be a possible reason. And between the two run they compared, a carbon cover was added which might influence the pedestal. So they did some study of the BPM pedestal values. The current cut Pengjia used before to select no-beam events is replaced by a more tight one. However, the results do not change much. More details can be seen in his slides here.

5/25/2016

Present: JP, Alex, Ryan, Toby, Chao, Jie, Vince, Ellie

Feature Presentations:

• Toby

Gave an update of his study on the scattering angle. The problem he mentioned on 5/11 has been solved. Both of the formulas are correct. However, he found that the central scattering angle jumped within one momentum setting for more than 3 deg. Chao mentioned that his calculation result does not show this behavior and they will discuss this offline. More details can be seen in his slides here.

5/18/2016

Present: JP, Karl, Alex, Ryan, Toby, Chao, Jie, Vince, Ellie

Feature Presentations:

• Chao

Gave an update of the acceptance study. He used the elastic scattering data to calibrate the resolution of the simulation. He found that the simulation package does not treat the resolution of the beam position properly. Thus the simulation package is updated to generate the events according to the beam profile. With this new update, the resolution of the simulation agrees with the data. More details can be seen in his slides here.

5/11/2016

Present: JP, Karl, Alex, Ryan, Toby, Jie, Vince, Ellie

Feature Presentations:

• Toby

Gave an update of the scattering angle calculation. He used two formulas from Pengjia and Chao to calculate the scattering angle and suggests that the results do not agree. People suggests that this two methods are equivalent and we should just use one of them. More details can be seen in his slides here.

• Ryan

Gave an update of his study of the scattering angle dependence of the cross-section. He used the radiated Bosted model and calculated the cross-sections with three different scattering angle. And the results shows ~20% difference. More details can be seen in his slides here.

• Jie

Gave an update on his study of the yield drift problem. He is still working together with Pengjia to correct the beam current dependence of the beam position. He summarized the beam current distribution for all production runs and found that ~90% of our data was taken with current less than 50 nA, where the beam position need to be corrected. He also studied the "sudden jump" of the beam position which means that the BPMA and BPMB readout did not changed much but the reported beam position changed a lot. It probably could be explained by the pedestal change but still need more study. More details can be seen in his slides here.

4/20/2016

Present: JP, Karl, Alex, Chao, Ryan, Toby, Jie, Vince, Ellie

Feature Presentations:

• Ryan

Gave an final update of the nitrogen cross-section study of the saGDH experiment. The radiative correction is done and the uncertainty carry-over from the elastic tail analysis is 1.5%. The radiative correction is calculated in two different way: the classic unfolding and the ratio of un-radiated and radiated Bosted model. He also did a bin center correction and compared the result with Vince's calculation. Two methods agrees at a 1-2% level. The radiative corrected cross-section for each kinematics setting is summarized in his slides and he will prepare a tech note for the analysis. More details can be seen in his slides here.

4/13/2016

Present: Karl, Chao, Ryan, Toby, Jie, Vince, Ellie

Feature Presentations:

• Jie

Gave an update on his study of the yield drift problem. Last time he showed some plots which indicates that the beam position might not be accurate and he did some study on this problem. He found out that the BPM readout shows some linear relations with the beam current. After carefully check the data, it seems that only the BPM B have this correlation. And this problem could be found in all beam energy settings. The uncertainty of beam position is very large if this problem is not corrected. More details can be seen in his slides here.

• Ryan

Gave an correction to his presentation on last week. He mentioned there was a mistake when he compared the formulation for the full internal bremsstrahlung tail and the angle-peaking approximation. And the results agree after the mistake was corrected. More details can be seen in his slides here.

4/6/2016

Present: JP, Karl, Chao, Ryan, Toby, Jie, Vince, Ellie

Feature Presentations:

• Ryan

Gave an update on his radiative correction study. He already studied the uncertainty for the elastic tail and he continued his study with the inelastic radiative correction. He explained how the angle approximation was applied in the internal bremsstrahlung. There is an equivalent correction in the angel approximation which is dropping the soft photons compare with doing a full integration. Difference between these two calculation is 5-10% for proton. He is still working on applying the calculation to other nuclei like Nitrogen. More details can be seen in his slides here.

• Toby

Gave an update on the his calculation of the asymmetry and cross-section. He applied the dilution factor calculated from the data to the asymmetry calculation. On the other side, he also applied the radiative correction factor calculated from the MAID model to the asymmetry calculation. He then applied the same factors to the cross-section calculation and got the cross-section and cross-section differences. The dilution seems not continuous and JP suggests to do a deeper study for each momentum in the longitudinal setting to understand what is the reason, for example the yield problem studied by Jie. More details can be seen in his slides here.

3/23/2016

Present: JP, Karl, Chao, Ryan, Toby, Jie, Vince, Ellie

Feature Presentations:

• Jie

Gave an update on his study of the yield drift problem. He continued his study with dilution runs. The method he used is similar as what he did for the production runs. He made a 6mm radius circle cut and compare the simulation result with the data. There are a few runs which were measured with beam current less than 50nA. After discussion with Pengjia, Jie mentioned that those runs' BPM readout might not be accurate since the BPM is calibrated at 50nA~100nA. He will do further study together with Pengjia to understand this effect. More details can be seen in his slides here.

3/9/2016

Present: JP, Karl, Chao, Ryan, Toby, Jie, Vince, Ellie

Feature Presentations:

• Toby

Gave an update on the dilution study. He summarized the dilution calculation for the 2.2GeV 5T transverse settings. He also used the dilution result to calculate the asymmetry for this setting. The radiative correction was considered in the calculation. And he concluded that the uncertainty of the calculation is dominated by the packing fraction uncertainty. More details can be seen in his slides here.

• Ryan

Gave an update on his cross-section analysis of the small angle GDH data. Based on the discussion from previous meetings, he checked the uncertainty of the elastic tail. The calculation includes three different sources: the correction factor representing higher order virtual photon diagrams, bremsstrahlung and multiple photon corrections. For the multiple photon corrections, he mentioned that G.Miller has an alternative multiple photon correction result. He applied the calculation to the saGDH data and it seems that the Miller multiple photon result is better representation of saGDH elastic tails. More details can be seen in his slides here.

• Jie

Gave an update on his study of the yield drift problem. He and Pengjia fixed the problem in the raster size calculation. He then made some cuts on the raster size to remove the boundary effect. He mentioned some of the runs had hot spot and was able to be corrected by the raster cut. He also summarized the yield spread with raster cuts for all kinematic settings. More details can be seen in his slides here.

2/24/2016

Present: Karl, Chao, Ryan, Toby, Min, Ellie, Jie

Feature Presentations:

• Toby

Gave an update on the dilution study. He need the scattering angle to calculate the scaling factor between the carbon and nitrogen. However, his study suggests that the scattering angle calculated for the carbon target is larger than the production target. The simulation shows opposite result which is expected to be reasonable from geometries. People suggests Chao to check the scattering angle calculation in the optics package. More details can be seen in his slides here.

2/17/2016

Present: JP, Jixie, Chao, Ryan, Min, Ellie, Jie

Feature Presentations:

• Chao

Gave an update on the optics study. He finished the matrix recalibration on right arm. The database is updated and is ready to use. The RMS values for angle and momentum calibration are summarized in his presentation. JP and Jixie has some concern about the broken septa seems to cause worse effect on left arm comparing with right arm. They suggested to check this more carefully. More details can be seen in his slides here.

• Ryan

Gave an update on his cross-section analysis of the small angle GDH data. Based on the discussion from the last week's meeting, he removed the extrapolation part in RADCON and then test the code with some test cross-sections from Pbosted Model. There is no problem in this case. So he compared the Pbosted model with saGDH data at large <math>\nu</math>. He is waiting for the response from Vince about the uncertainty of the saGDH cross-section at large <math>\nu</math>. More details can be seen in his slides here.

2/10/2016

Present: JP, Karl, Alex, Jixie, Toby, Chao, Ryan, Min, Ellie, Vince

Feature Presentations:

• Ryan

Gave an update on his cross-section analysis of the small angle GDH data. He is dealing the problem that after doing the tail subtraction and radiative correction the cross sections go negative at high <math>\nu</math>. He did a refit of the few low <math>Q^2</math> points using a charge form factor fit. The results still deviated from the PBosted model at high <math>\nu</math>. However, JP and Karl suggests that the code RADCOR code should not give negative cross section result. There might be some problems in the extrapolation part. Karl suggests to check the input data to see if there are constrains at the high <math>\nu</math> region. More details can be seen in his slides here.

2/3/2016

Present: JP, Karl, Alex, Jixie, Toby, Jie, Chao, Ryan, Ellie, Vince

Feature Presentations:

• Min

Gave an update on her acceptance study. She continued to compare the simulation result with data. Since the optics database is updated with the vertical beam position correction. The result suggests that the delta distribution is improved however the phi distribution still shows large discrepancy. She used this result to calculate the acceptance factor and applied it to the cross-section calculation. The result shows a factor of two difference. JP suggests that the acceptance calculated from the compare between the simulation and the data could still be influenced by the cross-section difference at small scattering angle. More details can be seen in her slides here.

• Toby

His presentation on 1/12 is reviewed. JP mentioned his concern about the uncertainty propagation. Toby is going to check it again and update his tech note about it.

General Discussion:

• The replay package is restored on the work disk.
• Toby will talk to Melissa and take over her packing fraction study.

1/26/2016

Present: Jixie, JP
By Phone: Jie, Chao, Ryan, Ellie

General Discussion:

• The analysis meeting will be moved back to 10 am Wednesday starting from next week.
• There is no meeting room available thus everyone will join by bluejeans. The meeting ID is 4828802914.

1/12/2016

Present: Melissa, Jixie
By Phone: Jie, Chao, Ryan, Toby, Ellie

Feature Presentations:

• Ryan

Gave an update on his cross-section analysis of the small angle GDH data. yield study using simulation. He is working on the problem that after doing the tail subtraction and running the inelastic Radiative Correction code the fully corrected cross sections go negative at high <math>\nu</math>. To solve this, he did a fit on the Nitrogen form factor. During the fitting, two models is considered: the oscillator model and the Fermi Model and the Fermi Model is proved to be better. He will complete the calculation of the elastic tail by using the form factor in a few weeks. More details can be seen in his slides here.

• Toby

Gave an review on the polarization uncertainty estimation. He claimed that the reason of the small uncertainties for the target polarization is because we took large amount of TE for each material. Thus the uncertainty of the calibration constant is reduced by average. Jixie suggests that the error propagation still need to be carefully checked. More details can be seen in his slides here

General Discussion:

• Chao updated his optics technical note.
• There is no meeting next week due to the Hall A collaboration meeting.

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