Dilepton

meeting

Date Every Day 11:30AM
Location F227 in general, except 5/5 in F224 and 5/11 in L207
Conference ID 	392477255
Desktop sharing and video https://bluejeans.com/392477255
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meeting system "bluejeans" howto https://hallaweb.jlab.org/wiki/index.php/Bluejeans_howto

program

SoLID_JPsi

TCS

DDVCS

emaillist

ee@jlab.org

register at https://mailman.jlab.org/mailman/listinfo/ee

code

• generator by Marie Boer and Michel GUIDAL
  • input file [1]
  • root file [2] (700MB on cloud)
  • note from Marie

It is a root file with 2000000 events. You have 4-vectors that correspond to the outgoing particle energies and momenta, 
kinematical variables: Phi_CMV and Theta_CMV are the gamma* CM angles, Qp2 is Q'^2, 
Egamma is energy of the beam and tt is t. ttmin is t_min. 
You can select "VirtualFlag==0" correspond to event generated from a photon beam 
and "VirtualFlag==1" from quasi-real photon, with a cut maximal Q2=0.3 GeV2.

To weight events you should use "W_tot_unpol". I am not sure yet of the polarized weights in some of the bins, 
so please let me check it before using it. 
You can nevertheless also use "W_BH" and "W_TCS" that correspond to "BH only" or "TCS only" contribution to the unpolarized cross sections.

Polarization vectors are probably not good in this version, please don't use it. The code is still in construction... 

I am doing some checks with the weights of the event generator. It seems there are some shifts when attributing  weights in the non physical part of the phase space. It comes when I generate the grid, I removed all "nan" in calculations but I introduced this problem. I will solve it today but it means I have to run a new table for cross sections. It is around 3 days.
 

• genTCS
  • https://jlabsvn.jlab.org/svnroot/solid/evgen/genTCS
  • BH from quasi-real electron and real photon on proton, home made

• grape-dilepton
  • http://research.kek.jp/people/tabe/grape
  • BH from electron on proton, used by the experiments at DESY/HERA
  • see details how to run it and analysis result at https://jlabsvn.jlab.org/svnroot/solid/evgen/BH/readme

• LPAIR
  • used by the experiments at DESY/HERA

• Compton2.0
  • BH from photoproduction, used by ZEUS

• GiBUU
  • http://gibuu.hepforge.org

(It may work on neutron also)
GiBUU does a good job with real photons on a proton (or heavier)
target.  It doesn't handle electroproduction as nicely (at least not the
last time I asked the Giessen group).
It is fairly straight forward to generate events, and there USED to be
good examples of input jobcards on the website, but they have been removed
recently while they upgrade.  I'd think the best route is to email them
directly to get the code and also ask for the example jobcards.