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Spin Duality Analysis Update
02/27/2008
Discussion on paper comments
- Two *somewhat* contradictory comments: click here
- Almost done implementing comments: the paper so far !
Checking PDFs
- Each PDF subroutine has 2 or more NLO sets
- I am looking into which set I should use for each PDF
- Duality sets at lower Q2 when TMC not applied !!! Here some plots to illustrate previous statement
- So I am checking my code.
06/15/2006
Target mass corrections
- Used formula in Sidorov & Stamenov's paper (hep-ph/0604092): plots
Working on systematic errors for all quantities
06/08/2006
Unpolarized cross sections
- Finalized systematic uncertainties --> inserted table in thesis.
Integrals
- Checked integral calculation. Now adding subroutines from Karl to calculate Extended GDH and BC sum rules, d2.
A1 Neutron
- Working on neutron extraction for A1.
04/27/2006
EPR analysis
- Applied polarization gradient using Xiaochao's method and static solution: 2.8%, 3.8% and 4.2% (relative) for I=5, 10 and 12μA. plot
- Very good agreement between calibration constants from water calibration and EPR-NMR calibration:
--> Cw = 3.18-3.19% per mV
--> Cerp-nmr= 3.17-3.18% per mV
Target systematics
- Vince gave me all the information from water and 3He NMR.
- Working on combining all systematics from target analysis.
Radiative corrections: unpolarized cross section:
- Several models will be compared:
1) Using scaled QFS to our data: plot, then generate a model with the same scaling coefficients: model at 25o, model at 32o
2) Using E94-010 σ0 and a)R=0.18, b)R=0.7Rp(HallC model), c)R from MAID(p+n) --> to get F2
3) maybe using MAID alone
- Working on feeding these model to RADCOR.F
04/20/2006
EPR analysis
- Applied polarization gradient: correction about 1.5-2 %.
- Beam relaxation effect= I/362 h-1: plot1
Polarimetry interpolation
- EPR-NMR comparison plot2
- Corrections for AFP and rotation loss: plot3, plot4
- Interpolation using only NMR measurements or using EPR/NMR average: plot5, plot6
Asymmetry
- New polarization has about no effect on asymmetries: para, perp
Comparison of polarimetry calibrations: Water vs. EPR-NMR calibrations
- Substantial difference between both calibration: NMR, interpolation
- Cepr = 3.30 % per mV, Cw = 3.18-3.20 % per mV. If I consider polarization gradient, Cepr = 0.95*3.30 = 3.14 % per mV.
- But again, about no effects on asymmetries: para, perp
Working on radiative corrections.
04/06/2006
False asymmetry
- here
Finalizing target polarimetry
- EPR: polarization gradient between pumping chamber and target chamber: about 1% --> here
- Investigating some discrepancies between NMR and EPR: here
- Working on the systematic uncertainties.
Working on model for radiative corrections.
03/23/2006
Beam energy
- Talked to M. Tiefenback on Tuesday.
- When energy value doesn't make sense after a pass change (= no fluctuation at all), it is because the monitor hasn't been restarted.
- He confirmed that the energy values I took for the analysis are good.
Neutron extraction
- Talked to Wally on Tuesday.
- Ian Cloet is working with Wally on the new spectral function.
- The spectral function for the resonance region needs to have a Q2 dependence: Δf(x) --> Δf(x,Q2)
- For the extraction of A1n by convolution:
--> need to extract g1n and g2n by convolution.
--> then with a model for F1n, I can get to A1n.
- The plan is for me to prepare a convolution code using Bissey spectral function for now. When Wally and Ian will have the new spectral function, I should be ready to implement it in the code. (Wally gave me a code that I can start to work with).
- I will have three neutron extraction method:
1) convolution with Δf(x)
2) effective polarization
3) convolution with Δf(x,Q2)
Working on model for radiative corrections.
02/23/2006
False asymmetries
- with acceptance cuts: right and left.
- N2 and carbon runs separetely: right and left.
- Both arms combined: here
- Questions: Do I need to correct for it ? If yes, how ?
Radiative corrections
- Working on unpolarized cross section model using E94-010 data:
σ0(Egdh,E'gdh,15.5o) --> F2(Q2,W) --> interpolation to the Q2 and W wanted --> σ0(ED,ED',25.0o)
- Using Hall C model for Rp and assuming R(3He) = 0.7 Rp: very preliminary F2 from E94-010.
- Very early model at 25o: here .
Working on corrections of Iguazu proceeding.
02/09/2006
False asymmetries
- Looked at false asymmetries with same binning as physics asymmetries, with same PID cuts but with differents acceptance cuts:
- no cut (very loose) on acceptance and all unpolarized runs included (even short ones): here.
- same as before but with same cuts on the acceptance as for physics asymmetries: here.
- same as before without short runs: here.
Exodus pressure curve
- no cut applied on W now: here
- obtained same result for Exodus density:
--> with W-cut: P = 14.53 +\- 0.15 atm that is in running conditions (T=320K), d = 12.4 +\- 0.1 amg
--> no W-cut: P = 14.57 +\- 0.14 atm that is in running conditions (T=320K), d = 12.4 +\- 0.1 amg
--> plot here
Working on my talk for the Graduate Student Lunch Seminar.
01/19/2006
Nitrogen cross sections
- Found a mistake in the nitrogen analysis: used psi instead of psig --> 1 atm difference --> xs are about 10% lower.
- Made the corrections and the corrected analysis note can be found here.
Nitrogen pressure curve for Duke (don't have one for Exodus)
- Details can be found here.
3He pressure curve for Duke and Exodus
- Running now.
12/15/2005
Duality on the neutron
- Interpolation of g13He at constant Q2: plot.
- Interpolation of g1p at the same Q2.
- Integration of g13He and g1p over the resonance region: plot of Γ13He
- extraction of Γ1n (res.) from effective polarization equation: Γ13He = PnΓ1n + 2PpΓ1p, plot of Γ1n
- Integration of g1n (DIS), obtained from several PDFs, over the same x range.
- Comparison of Γ1n (res.) with Γ1n (DIS): plot
Some issues to look at:
- g1 at the Δ(1232) for kin3 looks small: g1 vs. W, g1 at the Δ peak.
- Could be from target and/or beam polarizations, nitrogen dilution factors, density, ...
Target polarization final analysis:
- Applying AFP and rotation loss.
Elastic final analysis:
- Working on final elastic asymmetry
- Then will do pressure curves for Duke and Exodus
- Finally, elastic cross section.
Pizza lunch seminar on February 15, 2006
12/01/2005
A1 and A2:
- Comparison of A1 and A2 extraction from asymmetries and from g1 and g2: (3 GeV, 25o), (4 GeV, 25o), (5 GeV, 25o) and (5 GeV, 32o)
- A1 and A2 are not very sensitive to R but some discrepancies happen when using F1: the model for F1(3He) is not optimized yet --> need to wait for Wally to get the smearing function.
- For now, I will keep the method using asymmetries and R.
Duality on neutron:
- Xiaochao gave me subroutines to calculate g1n in DIS from different PDF models (plot): BB (by Bluemlein and Boettcher), LSS2001 (by Leader, Sidorov and Stamenov), AACPDF (by Hirai, Kumano and Saito) and GRSV2000 (by Gluck, Reya, Stratmann and Vodelsang).
- Working on integration of g1:
--> need to interpolate g1(3He) at constant Q2: chosen Q2 = 1.3, 2.0, 2.7 and 3.4 GeV2. IN PROGRESS
--> need to interpolate g1p at the same Q2. DONE
--> then can get for each Q2: I(n) = (I(3He) - 2 Pp I(p)) / Pn for any x (or W) intervals.
- Duality test: Jian-Ping suggested to follow the method from N. Bianchi, A. Fantoni and S. Liuti (Phys. Rev. D69, 014505, 2004):
--> integrate over the entire resonance region: 1.073 < W < 2.0 GeV (W will be translated in xbj).
--> integrate g1n (DIS) over the same xbj range.
--> take the ratio: I(res) / I(dis).
11/17/2005
- Nitrogen analysis done: systematic errors overestimated. Will work on it if we decide to publish the data in the future. The analysis note can be found here.
- Working on model for R(3He): some very early details.
- Will check the effect on A1 and A2 versus R models.
- Will study the model dependence on the radiative corrections: use E94-010 unpolarized cross sections combined with R models.
11/10/2005
- Finishing Nitrogen analysis
- Working on radiative corrections
- Working on model for R(3He)
11/03/2005
Nitrogen dilution
- Compared pressure slope between EPICS and target Logbook data:
--> same or very close for run #253, run #273, run #284, run #456, run #483, run #566, run #642, run #682, run #759, run #760.
--> different for run #296, run #338, run #390.
- So used Logbook pressure at the beginning of the run and extrapolate with the same slope as EPICS data to get end of run pressure:
--> run #296: 147psi --> 125psi becomes 130 psi
--> run #338: 147psi --> 125psi becomes 130 psi
--> run #390: 146psi --> 139psi becomes 133 psi
- regenerated cross sections with new density: plot. The difference is about 1-2% relative.
- working on the scaled QFS model: made some improvements
--> old scaled scheme: plot
--> new scaled scheme: plot
XS(DELTA)*1.5
XS(1500)*1.2
XS(1700)*0.02*Q2
XS(DIS)*3.0*(E-NU)*sin(theta/2)/Q2
--> need some improvements because low W behavior of the model undershoots 4GeV data.
New code for analysis
- Before I had several codes for each step of the analysis.
- Now only one that extract cross sections and asymmetries from histograms, combined both arms data, formed polarized cross section differences, applied radiative corrections and formed g1, g2, A1 and A2.
- So far the new code gives the same results as the other codes.
- Still need to add nitrogen dilution correction and extraction of the neutron SSF.
10/27/2005
- Writting proceeding for Iguazu conference.
- Bringing all my codes in one code that will go from histograms to structure functions.
09/22/2005
Duality 05 proceeding submitted
R(x,Q2) for 3He
- Hall C results for the proton and deuteron: see slides
- R for the proton at RSS kinematic (Q2~1.3 GeV2): plot
- Meeting with Wally at 2:00pm about R(x,Q2) for 3He and neutron extraction.
Plan
- extract A1 and A2 with new N2 dilution and new model for radiative corrections: using R3He and E94-010 unpolarized cross sections --> F2
09/15/2005
Nitrogen dilution done
- New dilution values significantly different: see plot
- New 3He unpolarized cross sections: see plot
- Finished writing the analysis note about N2 data. Will be on E01-012 website soon.
Waiting for final comments on Duality 05 proceeding
Having computer problems
Plan
- extract A1 and A2 with new N2 dilution.
09/08/2005
- Duality 05 proceeding.
09/01/2005
Nitrogen dilution
- Large thicknesses difference between reference cell and Exodus:
--> Window: Exodus = 101um, Ref. = 126um (22% difference)
--> Wall: Exodus = 1.17mm, Ref. = 1.56mm (29% difference)
- This affect only 3GeV data (and kin.6.3, I forgot to look at it !).
- Compared results from scaled QFS with Exodus and Ref. cell ticknesses: see plot
- Applied the correction to the nitrogen radiated cross section.
- This large thicknesses difference create a tiny variation of 0.3% in the ratio XS(N)/XS(3He).
- Nitrogen dilution is about 7-8% of the 3He cross section: see plot
- Nitrogen analysis report almost done.
Plan
- Duality 05 proceeding.
- Neutron extraction.
08/25/2005
Nitrogen dilution
- Finished the radiative corrections: see plot
- Now finishing a report about nitrogen analysis
Beam Energy --> from Tiefenbach measurement:
- 5GeV energy drop: plot
- After weighted average on all runs:
--> 1046.06 +/- 4.76417E-02
--> 3028.13 +/- 0.263393
--> 4017.86 +/- 6.23422E-02
--> 5008.35 +/- 7.36510E-02 or 5019.89 +/- 7.23394E-03 if considered the energy before the drop
Working on duality 05 proceedings
08/04/2005
Nitrogen dilution
- Calculated radiation lengths for reference cell filled with nitrogen.
- Nitrogen cross sections compared to nQFS radiated: see plot
--> QFS overestimates DIS cross section
- QFS = incoherent sum of cross sections = QE + DIP + DELTA + RES(1500) + RES(1700) + DIS
- Need to find a scaling factor that works for all kinematics in order to get a good model for 3GeV missing data:
--> 1st try: RES(1700) + DIS --> (RES(1700) + DIS)/(0.7*nu*Q2), see plot. Looks pretty good but violates dimension equation.
--> now studying QFS-data discrepancies versus Q2, nu, W.
Neutron extraction
- waiting for Hall B proton data.
- waiting for R from Hall C.
- preparing code for neutron extraction.
05/12/2005
Radiative corrections
- Kinematic coverage needed for 3GeV data R.C: see plot
- Model for R.C.:
--> Used g1 and g2 E94-010 data interpolated at our needed kinematics.
--> Then extracted dsigpara and dsigperp at the same angle as our data (25o) and at constant energies.
--> model
- Ran external R.C. on our data before smoothing them: see plot
- Smoothed data: see plot
- Now doing external R.C. on smoothed data.
05/03/2005
- Generated Nitrogen cross sections with same cuts as for pol.3He data.
--> good data coverage for kin 4, 5 and 6.
--> At 3GeV, we can use QFS scaled to the data.
--> see plot
- Radiative corrections on polarized cross sections:
--> polarized elastic tail negligeable: plot
--> at first approximation, ignore QE radiative tail.
--> 1st test: external radiative correction on kin 5 (5GeV, 25o) using 3 and 4 GeV data as an input model: plot
--> now writing code to interpolate E94-010 data at any (Q2,nu) points needed for 3GeV R.C.: Q2 vs. nu, Q2 vs. W
04/19/2005
- Put on website density analysis report (see analysis report #5).
- Radiative corrections:
--> calculated radiation lengths for all possible configurations during E01-012 (see analysis report #7).
--> calculated the kinematic area needed for the RC: Ep vs. Es or Q2 vs. W.
--> looked at N2 elastic radiative tail (corrected for density: R=dN2/dHe3): kin.3, kin.4, kin.5, kin.6.
--> now working on N2 inelastic substraction (from data and nQFS).
--> Then need to find data or model of cross sections at lowest energies.
04/05/2005
- Extracted external field magnitude from EPR baseline resonance by solving the following equation at different orders:
Fres/Fhf = x/6 + 5x2/36 + x3/6 - x4/16 + O( x5) where x is proportional to B.
click here
- Comparison of the external field magnitude from the two methods: click here.
--> The difference between the two methods is about 0.25G
--> can be due from other magnetic sources (spectrometer magnets, earth field) and from not having a calibration for the small coil power supply.
- Calculated EPR constant: click here.
- Extracted polarization (= pumping chamber polarization) from EPR
--> for all measurements
--> during the production time.
- Now working on polarization transfer between the pumping chamber and the target chamber.
03/29/2005
- Target density for each run: click here
- Uncertainty on the density:
--> varied the target chamber and/or pumping chamber (wall) temperatures by +/- 5K.
--> Then looked at the density variations (see table)
- Comparison of parallel and perpendicular unpolarized cross sections with new densities: (left, kin3), (left, kin4), (left, kin5), (left, kin6), (right, kin3), (right, kin4) and (right, kin6)
- Now I have all pol.3He and reference cells characteristics: thanks to Vince and Jaideep.
- Replayed runs for pressure curve analysis and for final elastic analysis.
- Working on EPR:
--> Holding field magnitude: the calibration of the Helmholtz coils was done before we changed the Kepco. Here a plot of the holding field magnitude (B0) calculated from the coil current and calibration at the time of EPR measurements.
--> now working on extracting B0 from EPR resonance frequency.
03/22/2005
- click here
03/15/2005
- click here
03/08/2005
- Extract RTD at the beginning of each run (plots)
- We noticed a jump in the target chamber RTD readout for run# between 400 and 500. Will look at the cause.
- Used a polynomial fit to estimate the target chamber temperature.
- Compared with Jensen's method (only when RTD#4 is working) and with a linear fit: the difference is less that 0.5%.
- Jian-Ping pointed out that RTD#1 on Duke wasn't right: might have an offset.
03/01/2005
- click here
February 2005
- Organized all polarimetry data.
- Extracted EPICS target variable values.
- Made a polarimetry summary table for on-line results.
- Fitted all NMR and EPR spectra.
- Made a new polarimetry summary table for new results.
01/27/2005
- click here
01/20/2005
- click here
12/09/2004
- part 1 and part 2
12/02/2004
- Acceptance cut study for the cross section: plots
- PID cut study for the cross section: plots
- We can see a big difference between both PID cuts in the left arm at low W. It might be due to the low energy electrons that the cerenkov doesn't cut away (see red tail at E/P < 0.5) :plots
11/18/2004
- click here
11/11/2004
- click here
11/04/2004
- See a dramatic behavior of the cross section when I looked at each momentume setting separately: plots
- Jian-Ping and Nilanga adviced to use the Mott cross section for the correction and the best way is to implement it in the simulation.
10/21/2004
- Used the new VDC and scintillator efficiencies to generate new cross sections.
- Comparison of cross section with different PID cuts: all PID cuts applied, cut only on EM calorimeter, cut only on cerenkov ==> the cross sections are stable. Only for the kinematics at (5 GeV, 25deg) there is a little offset as Jian-Ping pointed out.
- That might be due to the underestimate of the efficiencies. I have to look closer at the fit of the electron E/P peak used to estimate the loss of electrons.
- In summary, there is no problem with cerenkov mirrors or lead glass blocks since the cross sections with the 3 different PID cuts are identical.
- Working on removing pion rejector 2nd layer (PRL2) from the analysis for kin 4.2 because block 4 had a bad base ==> calculation of the efficiency of PRL1 by itself.
10/14/2004
- Working on efficiency: need to use QFS to remove the cross section dependence of each block.
- changed binning method for the cross section as Zein-Eddine suggested: now binning in W ==> dependence in dp, ph_tg, th_tg.
- Cross sections are smoother: better overlap between momentum settings but problem at the lowest and highest W values for each energy --> need to check the code.
10/07/2004
- VDC efficiency done. Only uncertainties have to be estimated.
- Looking into cerenkov and EM calorimeters efficiencies for each mirror and each lead block.
- Jian-Ping suggested to normalize the number of events in each mirror (or block) by the cross section since cerenkov and EM calorimeters have a dp dependence.
09/30/2004
- Changed ESPACE in order to add non-cluster variables for preshower and shower.
* little change in preshower and shower spectra.
* no change for the pion rejector as it should be.
- VDC efficiency study with cuts on good electrons applied (main trigger and PID cuts):
* Jian-Ping pointing out that it was not normal that I didn't see any zero track events in the preshower-shower spectrum.
* After looking at it just after the meeting I saw that I had an "indirect" cut on dp. When removing this cut, zero track events are scattered all across the preshower and shower: see left, see right (only the cerenkov cut is applied in these plots in order to show clearly the distribution of each type of events in the preshower+shower spectrum).
* new efficiencies: left, see right.
- Rechecked the trigger efficiency --> no changes. See here
- Redid cerenkov cut efficiency with the same upper limit cut as I am using in the cross section analysis (350-10000) --> negligeable changes.
09/02/2004
- Writting proceeding for GDH 2004
- Cross section analysis:
* adding shift in ytg or phitg doesn't create a significant change in the cross section. JP suggested to look at a shift in dp.
* For the left arm, the xs drops depending of the pid cut applied: cerenkov only or cerenkov + lead glass: see here. However the right arm xs stays stable: see here.
* So looking into pion rejector calibration and efficiency as a first step..
05/06/2004
- Working on nitrogen dilution:
* will use nQFS to estimate the corrections due to the different wall thicknesses between Duke and the ref. cell in the resonance region.
* will use Monte Carlo for Elastic with Nitrogen form factors in.
- Showed A1 and A2 for 3He in function of Nachtmann scaling variables.
- Comparison with E99-117 3He data before radiative corrections.
04/22/2004
- E. Chudakov gave his estimate of the beam helicity ==> only 3 GeV data has to be flipped.
- removed runs with high charge asymmetry or "wierd" livetime.
- Study of the asymmetry behavior versus PID cuts for electrons: no big changes seen so far.
- Showed the pion asymmetries and asymmetries with no PID cuts: large pion asymmetries at 3GeV.
- Showed for the first time A1 and A2 for 3He.
04/15/2004
- Study of PID cut effects on asymmetries:
* loosing the cuts doesn't have a real effect.
* tighting the cuts on cerenkov (1500 - More checks are under way.
04/08/2004
- Study of PID cut effects on asymmetries: didn't see noticeable changes after tightening the cuts ==> pion contamination is very small.
- Jian-Ping suggested to relax the cuts and look at the effect of pions on asymmetries.
04/01/2004
- Changes made in ESPACE: make Bodo's subroutine for BPM/raster calibration active and put back sieve position for Duality.
- BPM/raster calibration for 1 GeV data is done.
- Asymmetry analysis checks:
1) check configuration for all runs by comparing Halog and runsheet entries ==> found several mistakes.
2) check target position to make sure it was Pol. 3He runs. (no mistake found)
3) check momentum settings. (no mistake found)
- Regenerated asymmetries:
1) after correcting the mistakes in the configuration.
2) after removing runs with all problems (DAQ crashed, ...) + step 1
3) after tighting cut on target windows + step 2 (before cut on ytg was +/- 0.065 and now it's +/- 0.050).
- Comments: 4 GeV asymmetries look to have the wrong sign --> need to look at spin precession versus energy.
- Plots: 3GeV-25deg, 4GeV-25deg, 5GeV-25deg, 5GeV-32deg.
- Jian-Ping suggested to check configurations in the middle of runs.
- Nilanga adviced to look at the behavior of the asymmetries with tigher PID cuts.
03/25/2004
- Problem to recompile ESPACE due to LINUX upgrade: Seonho fixed it.
- BPM/raster calibration for kin.1. (all the other kinematics were already done)
- Working on adding old shower variables (= not build from tracking information) in ESPACE in order to extract the VDC efficiency.
- Checking analysis steps.
03/04/2004
- Modified the asymmetry code to extract cross section.
- Generated cross section for all kinematics:
--> inefficiency of preshower blocks #8 and 16 caused glitches of the cross section for kin3 and kin6.
--> will look into using only the shower for these kinematics.
- Compared xs with nQFS and E94-010 data (for the lowest Q2)--> the shapes are pretty consistent but the acceptance wasn't taken into account properly (as Nilanga and Jian-Ping suggested) so had to multiply by a factor 3 nQFS to agree with the data for kin3 for example.
- Early elastic cross section: simulation and data have a 3.7% disagreement for the left arm and 6% for the right arm.
- Plan: Acceptance study, target analysis, finish detector efficiencies.
02/26/2004
- Showed W peak position and width versus run for elastic kinematic: width and peak position is very stable.
- Regenerated Elastic asymmetry with same cut applied to data and simulation
* left arm average asymmetry = (4.045 +/- 0.258)% and Monte Carlo simulation gives 4.101%.
* right arm average asymmetry = (3.839 +/- 0.210)% and Monte Carlo simulation gives 4.129%.
- Jian-Ping said that the cuts are too tight for asymmetry analysis.
- The W peaks of simulation and data don't match too well: Alexandre and Jian-Ping suggested to look at the spectrometer resolution.
- When plotting Y_tg for the empty reference cell and the pol. 3He cell, the target windows don't match for the left arm however it looks good for the right arm --> have to check it.
- Plan: elastic cross section then will go back to elastic asymmetry.
02/19/2004
- Showed elastic asymmetry generated with a cut on the elastic peak.
- After removing bad runs and short runs:
* left arm average asymmetry = (3.890 +/- 0.144)% and preliminary simulation gives 4.126%.
* right arm average asymmetry = (3.513 +/- 0.138)% but no simulation done yet for the right arm.
- The right arm asymmetries show some strange behavior that has to be investigated.
- Jian-Ping suggested to check the possible bleedthrough of Hall C in Hall A beam during Spin Duality.
- Seonho suggested to study the stability of the elastic peak position for all runs in order to check if we didn't have a problem at the time with the right magnets.
- Plan: continue elastic analysis.
02/12/2004
- Used the very very last version of ESPACE (sept. 2003).
- Regenerated all asymmetries: now elastic asymmetries looks good (except no cut on elastic peak has been applied) --> sign change can be seen at configuration change.
- Asymmetries stay unchanged for all other kinematics.
- Cerenkov cut efficiency: due to the pion contamination in the shower electron sample, the true efficiency should be evaluated at the lower W of each energy.
- Plan:
* continue elastic analysis.
* finish efficiency evaluation for all detectors.
* look at asymmetry variations by changing cuts.
02/05/2004
- Cerenkov cut efficiency for all runs (except elastic): Jian-Ping pointed out the strange behavior in the left arm --> to be checked.
- Trigger and VDC efficiencies for electron. For VDC efficiency, should have cut on shower and preshower variables that don't contain any tracking requirements --> to be done again.
- Elastic analysis: after a lot of struggles and checks, the ESPACE version used to do the analysis seems to be the problem.
- Plan:
* Solve elastic asymmetry problem and then run the simulation.
* Go to cross section analysis.
* Trigger, VDC and lead glass electron efficiencies for all runs. Jian-Ping suggested to do the same thing with pions at the same time.
01/29/2004
- Showed trigger efficiency but a cut is missing on ntrack=1 in the trigger efficiency analysis.
- Showed VDC efficiency for each kinematic with different cuts. Jian-Ping suggested to extract the VDC efficiency for electons selected by the PID analysis.
- Then will have to do the parallel analysis for pions.
- Jian-Ping adviced to extract the efficiencies for all runs (not only for each kinematic).
01/22/2004
- Looked at the VDC and trigger efficiencies but didn't applied the proper cuts. So have to do it again.
- Started to work on the elastic analysis: comparison of the target variables with the simulation without applying any cut on the data.
01/08/2004
- Used an older version of ESPACE from Seonho than the one used in her analysis so far.
- Now all elastic runs can be replayed.
- But still several runs show a number of events equal to -1 at other energies.
12/16/2003
- Found the problem with the deadtime calculation.
- Showed preliminary false asymmetries using only carbon runs. Jian-ping and Alexandre suggested to use all unpolarized target data.
- writting report on detector efficiencies.
Plan
- VDC and trigger efficiencies.
- Elastic analysis.
- Target analysis.
12/04/2003
- did Cerenkov cut efficiency analysis in a different way (read in Xiaochao's thesis).
- then re-ran the PID efficiency analysis with the new cuts on Cerenkov.
- regenerated the asymmetries after removing short runs and applying new PID cuts --> no obvious change in the asymmetries.
- listed runs with high charge and/or deadtime asymmetries.
- compared Ring Buffer and Scaler quantities: just for a few runs they disagree. Will have to find out the reason.
Plan
- Quick look at VDC and trigger efficiency.
- Elastic analysis.
- Target analysis.
10/16/2003
- BPM/ raster correction done: about (50 * 2) runs needed to be corrected for beam drifts.
- Regenerated all Ntuples and now creating all histos.
- Looking at VDC's Ntrack=0 problem --> at the first look, the problem doesn't exist anymore in these Ntuples.
- Comparing Ring Buffer and scalers
- working on pion rejector re-calibration.
Plan
- Be done with all above before leaving to France.
- Then will start elastic analysis.
10/09/2003
- Elastic and delta asymmetries at E=1GeV.
- Looking into pion rejector calibration.
- regenerate ntuples without using filter.f
- a lot of elastic runs failed at the replay.
Plan
- BPM/raster calibration by correcting for beam position drifts.
- comparison between Ring buffer and Scalers data.
09/25/2003
- BPM/raster analysis with no correction done for 3, 4 and 5 GeV data.
- produced ntuples and histos with the new raster/BPM variables.
08/21/2003
- see slides here.
06/18/2003
- Pedestal runs analysis:
--> unable to use ESPACE to extract all pedestal positions
--> used pedestal files that Bob Michaels generated during the experiment.
- Cerenkov calibration:
--> with new pedestal values, redid Cerenkov calibration.
--> determined gain coefficients by aligning single photo-electron peak at channel 200 (for both arm).
--> fluctuations and incertainties in the right arm are due mostly to mirror #3 and the low statistics at 5 GeV.
- Pion rejector (left arm):
--> after using the new pedestal positions it looks like only 2 different calibrations will be needed (before 3 needed)
--> still checking
- Preshower-shower (right arm):
--> when started to look at the PID efficiency, discovery of a big problem from the calibration that was obvious in the preshower%shower plot.
--> the strips seen are from a bad calibration of the preshower.
--> after several tests, I realized where my mistake was: I supposed the calibration software determined the pedestal positions.
--> after using the new pedestal values (from pedestal run analysis) and re-running the calibration software, the preshower%shower plot looks much better.
--> still checking and working on it.
- Plans: finish PID calibration + efficiency, generate asymmetries.
04/10/2003
- Pion rejector calibration: resolution 38% (bad !!!).
- will try another method to calibrate it.
03/27/2003
- the right arm shower calibration is done: it was just a problem of the detmap.
- the energy resolution is 6-7% with the preshower+shower counter.
- gave a dry talk for APS meeting.
03/20/2003
- contacted Armen about the shower calibration. Seonho thinks that the problem is coming from the detmap.
- replay is done, now improving code to get asymmetries
03/13/2003
- preshower-shower calibration: working on it.
- asymmetries: used the wrong ESPACE version on the last replay, so replaying again.
- preparing APS talk.
02/20/2003
- EPR-NMR calibration on Exodus: only the 3 last measurements can be taken into account since the polarization wasn't uniform in the cell yet.
- Detector calibration: Left and right cerenkov are done. Now checking the efficiency of each mirror.
- Plan:
--> finish detector calibration,
--> asymetries for each run with the new detector calibration,
--> target polarization analysis.
(last updated: 06/08/2006, maintained by Patricia Solvignon)