Global PID Meetings


This meeting is to discuss the status for DC06.


This first meeting focused on presentations by the sub-detectors on their current PID performance. The following are a list of questions or issues raised during the meeting.


  • How will the reference distribtutions used to create the dLL values by produced from real data ?
  • Evidence for 'mistakes' in tracking MC associations (Electron-like conponent to background distribution)
  • Can Electron ID be better optimised for tagging
  • Binning effects in reference distributions can be seen in DLL values. To be removed using smoothing procedure (KEYS)
  • Further work on brem. corrections for electrons ?
  • Why do DC04 parameterisations compare badly to those from the TDR data ?
  • What is the procedure to calibrate the CALO system with real data ?


  • Warning that the hit rate in M2 has been seen to increase by 20-30% with latest detector description. Need to see a more detailed study to understand where exactly this is coming from. Need to retune the muon ID accordingly.

  • Why does the muon ID for two dLL values for the combined particle ID ? Can they be rationalised ?
  • dLL calculation should be done by muon ID pacakges. Should not be internal to protoparticle maker.
  • Use of "NoSharedHits" algorithm seemed overly complicated for the end user.
  • What is the procedure to calibrate the MUON system with real data ?


  • What is the nature of the structure in the PID efficiency curves around 10 GeV for DC04 and RTTC data ?
  • What about the positive/negative track asymmetry in the kaon ID ?

Combined Particle ID

  • Why are some recommended dLL cut values so far from zero ? Are all the likelihoods properly normalised ?

ChrisRJones - 17 Nov 2006

This topic: LHCb > WebHome > LHCbComputing > GlobalParticleID > GlobalPIDMeetings
Topic revision: r1 - 2006-11-17 - unknown
This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
or Ideas, requests, problems regarding TWiki? use Discourse or Send feedback