Agenda

  1. Pass6                                                         – Nathan and Rafo
  2. ECAL Crystal Positions                              – Jeremy
  3. Modifications of Tracking to include ECAL – Bradley
  4. Questions?                                                 – All

Notes

ECAL Crystal Positions - This code needs to move to the trunk soon. An issue may be how the lcdd writing component deals with the conditions database. We need to have the capability of creating a detector for simulation that is identical to the actual detector for a specific run (or run period). This would require the input of the run number into the detector description, which it seems requires a change of that part of the system.

Tracking extension - There were a lot of good suggestions for Bradley. '

  • If only using the ECAL hit positions, then you can create a dummy tracking layer, put in the HelicalTrackHits from the ECAL info.
    • The ECAL hit position is actually not that great, so it is not clear how much this would help.
  • The energy of the ECAL is the more useful information to use. This will require more fundamental changes to the tracking.
    • An issue here is that we have lots for tracks near the edge of the ECAL, where the energy resolution is not so good, and not fully understood.
  • Perhaps it would make sense to first (only?) add the ECAL information for the GBL stage of tracking.
  • It seems that it would be good to study these issues first, specifically, how many tracks could be helped by using the ECAL?

 

Low Momentum Tracks - The ECAL discussion lead to lots of conversation about the "inefficient low momentum tracks". We looked again at Matt's plots, which show that Monte Carlo has fewer tracks for electrons at high momentum than the MC. Sho had already indicated this is probably the gap in the first row of the ECAL, but that does not explain why the MC looks so different.

  • This would be very sensitive to detailed crystal position. The X position of the crystals is currently not corrected => We need Ani's ECAL geometry implemented.
  • The base MC does not have the Wide Angle Bremsstrahlung mixed in. This should be added.
  • Bradley showed that the EGS5 output seems to have a generator cut at 0.65 GeV, suspiciously close to the energy where the electrons die out in MC. He will look at generating a sample where this cut is absent.

 

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