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Sanity check for tracking media in EEMC

Updated on Fri, 2009-07-17 16:00. Originally created by jwebb on 2009-07-17 15:34.
Abstract:  Comparison of muon energy deposit in 1st layers of EEMC and BEMC in gstar we've shown that the MC deposits too little energy in the lead and scintillator of the EEMC, compared with the BEMC and with what we expect given published mean dE/dx values and the construction of the endcap.  In this note we check that the MC has reasonable values loaded into the geant lookup tables which govern physical processes in tracking media.

1.0 GEANT Configuration

Default geant, no modifications to geometry.

2.0 Muons in the first lead radiator

Figure 1 below shows the muon dE/dx vs incident kinetic energy for both the barrel and endcap calorimeters in lead.  It also shows the mean free path for muons in lead.  The MFP is calculated using the cross sections of all activated physical processes.  In both cases the barrel and endcap calorimeters are being initialized with the same values.

Figure 1 -- Muon energy loss (left) and mean free path (right, despite the title) in the lead tracking media for both the barrel and endcap calorimeters.

 

Figure 2 -- Muon energy loss (left) and mean free path (right) in the polystyrene tracking media for both the barrel and endcap calorimeters.

3.0 Conclusions

Given the previous study, there is something wrong with the MC which results in a different treatment for muon energy loss in the first layers of the endcap and barrel calorimeters.  That difference does not appear to be a difference in the configuration of the materials used in each calorimeter.

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