-- RainerNovotny - 26 Apr 2006

Possibilities of the EM-Calorimeter to contribute to PID

The EM-Calorimeter, based on PWO crystals, provides in case of optimum read-out capabilities a good energy resolution for particles and photons (light quenching for MIPS ~ 1], time information well below 1ns above an energy deposition of > 100 MeV (might be even further improved) and position information due to the fine granularity of the calorimeter (single crstal front face ~ 2cm x 2cm) and a reconstruction of the impact point in case of shower formation (resolution ~ 1-2mm).

The following aspects for PID could be considered:

• energy measurement: in case of low energies (<400MeV for protons) the full energy can be deposited in 200mm of PWO, therefore complementary to tracking. It could be even used to measure the low energy part of muons.
• PID: the correlation with an energy deposition in the plastic-TOF-barrel could be used to some extend as a telesope for energy-loss/energy correlations (for sure for low energy particles).
• shower and hit pattern: the large difference of the hit pattern of responding detector elements near the point of impact will allow to discriminate or identify particles (low multiplicity) and photons/electrons. It could, for example, be used to discriminate between photons and pions. In addition, the reconstracted point of impact can be correlated with the tracking information.
• time information: The present data with APD read-out but very preliminary read-out circuits have shown aready the capabilities of sub-nanosecond timing. One can consider time resolutions below 1ns even at 50 - 100MeV and values well below 400ps above 500MeV. These resolutions are not sufficient for TOF due to the short target-detector distance but allow time correlations with tracking or the DIRC. In addition, it can provide an excellent tool to discriminate background caused by different interaction points etc.

-- Included by GeorgSchepers - 26 Apr 2006, awaiting approval of Bertram Kopf: Bertram made some PID-Studies for the EMC still in the old framwork.

For this he regarded only the energy deposit in the crystals und the reconstructed tracks (Matching). (All after the RECO and not based on some MCtruth). If one takes in addition the shower shapes, time information, etc., the PID with the EMC probably becomes better still.

• Bertram Matching: Track PED:
  

• Bertram PID with EMC: