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Recent simulation studies in the EEMC and BEMC

Updated on Mon, 2009-07-20 10:26. Originally created by jwebb on 2009-07-19 15:27.
Summary of recent simulation tests in the EEMC and BEMC

0) Hal and Keith have looked at the pT,eta dependence of the sampling
   fraction of the EEMC... which we've known for some time isn't flat. 
   To investigate further they looked at a small simulation throwing
   single muons, and find too little energy deposited in the various
   layers of the endcap.

http://drupal.star.bnl.gov/STAR/blog/spinka/2009/jul/06/eemc-simulation-studies-progress

1) Mike has looked in the barrel for nonlinearities in the sampling fraction
comparable to what we see in the endcap.  The study compares the sampling
fraction (E_reco / E_thrown) as a function of eta to the expectation from
the BEMC slow simulator.
 
http://drupal.star.bnl.gov/STAR/blog/betan/2009/jul/20/sampling-fraction-current-bemc-geometry

2) Since the tails of the muon dE/dx distributions are fairly long,
   one really needs to sample them lots of statistics.  So I dug out a
   geant manual and made histograms of the energy lost by muons as they
   traverse the first lead layer and scintillator of the EEMC and, for
   comparison, the BEMC.  The BEMC agrees reasonably well with
   expectations given the amount of material, but the EEMC falls 20%
   short.

http://drupal.star.bnl.gov/STAR/blog/jwebb/2009/jul/16/comparison-muon-energy-deposit-1st-layers-eemc-and-bemc-gstar

3) As a quick cross check, I made sure that the energy loss and cross
   section tables stored in GEANT at program initialization are
   consistent.  They are.  Geant _should_ be simulating dE/dx
   consistently...

http://drupal.star.bnl.gov/STAR/blog/jwebb/2009/jul/17/sanity-check-tracking-media-eemc

4) Mike has looked at varying track transport thresholds for e-, gammas in the barrel, and finds no significant variations.  This is similar to studies Weihong and Jan showed for the EEMC some time ago.

http://drupal.star.bnl.gov/STAR/blog/betan/2009/jun/23/geant-tune-study

 

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