TRD Software Summary

1
TRD Software Summary

• Christoph Blume
• University of Frankfurt/M

2
Position Resolution (Christian)

• Comparison of test beam data to AliRoot
  simulation
• Configuration AliRoot geometry, use one TRD
  sector, other detectors off
• Space charge effects?
• Agreement between simulation and data better for
  15º incidence angle than for 0º
• Parametrization in AliRoot digitizer?
• Effect of filter Better position resolution with
  2exp
• But 2exp deteriorates S/N ? e/p separation

3
Position Resolution (Christian)
s(residual point) good agreement simulation ?
data
However factor 2 difference in s(angle)
4
TR Simulation in Geant4 (Christian)

• Simplified setup
• Effect on position resolution
• Understanding of TR simulation and tuning in
  Geant4
• Test propagation of TR photons into next layers

5
Energy Loss Simulation (Ken)

• In order to avoid double counting of
  d-electrons Consistent scheme, implemented in
  Geant3 routine
• Ermilova or standard Geant?
• Comparison of current implementation to Geant3
• Current Ermilova steps for each primary
  ionization
• Geant3 1/E2
• Compare in region lt 50keV (lower limit for
  d-electrons)
• Fluctuations?
• Current conclusion no need for Ermilova

6
Energy Loss Simulation (Ken)
Microsopic approach results in step size too
small for Geant (Edep) (typically 0.1mm) ? zero
entries
Need for microscopic approach? dE/dx for each
time bin only?
7
Reconstruction (Jana Marian)

• New comparison macros for reference points
• Classes and macros already submitted to CVS
• On going work on cluster finder
• Work on parallel tracking by Marian
• Standard tracking?
• Should be maintained as baseline option

8
Fast Simulation (Tariq)

• Fast simulation framework running
• Parametrization of central barrel tracking
  (ITSTPCTRD)
• Resolution for pions
• Input
• Backgound parametrized HIJING
• PHYTIA (CTEQ4L) 115 c/cbar, 5 b/bbar
• J/Y, ? Generator from AliRoot library, rate
  y-distribution need to be checked
• To do
• Parametrizations for electron tracking
• Correlations between pt, ?, f resolution
• g-conversions from p0 decays before ITS (lt2 ?)
• PID from TPC

9
Raw Data Generation (? Bogdan?)

• Implementation of raw data generation needed
• Needed for impending data challenge
• Existing for TPC ITS
• TRD next largest contributor to data volume