Tracking without Magnetic Field E. Rodrigues, NIKHEF LHCb Tracking and Alignment Workshop, Lausanne, 8-9th November 2006

1
Tracking without Magnetic FieldE. Rodrigues,
NIKHEFLHCb Tracking and Alignment Workshop,
Lausanne, 8-9th November 2006
1. Motivations 2. Problems at Hand 3. Software
available 4. What we know so far / has been
done 5. Open Discussion
2
Motivations

• Getting ready for day 1
• Pilot run in 2007 will be with field off !
• LHC machine commissioning start September 2007
• Alignment pilot run
• Bound to be done with field off first
• - experience shows alignment easier with B 0
• - decouples detector issues from B-field
  effects

3
Problems at Hand

• Software commissioning
• Pattern recognition needs to work correctly with
  field off
• - purity matters, efficiency is of second
  order importance
• Fitting needs to cope with straight tracks
• - momentum determination is the key issue
• Need to identify extra tracking software for
  tackling the problems raised by the above
• - algorithms, tools, python scripts for quick
  tests, etc.
• Link with Alignment issues
• Alignment is a demanding customer of tracking
• ? discuss with experts what still needs to be
  developed

4
Software available (1/2)

• For Pattern Recognition
• Our present algorithms
• - Velo tracking, forward, matching, etc.
• But need to identify 2007
• - which PR work with field off, tuning,
  performance
• - which are necessary, and minimize set of
  them
• For Track Fitting
• Our standard set of fitting tools
• - Kalman filter, extrapolators, projectors,
• Track event model
• do exploit, please, the great potential of
  trajectories
• and the rest of the TEM

5
Software available (2/2)

• Open Velo Tracking
• Works by design with field off
• Publicly in CVS ready to be used and tested
• Software from aligners
• Full account in talks on alignment
• Other Tools available
• E.g. TrackCaloMatch
• - matches tracks with calorimeter
  clusters
• - used in field off to estimate a
  tracks momentum

6
What we know so far (1/3)

• First investigations
• First presented at Joint OT/IT Software Meeting
  at NIKHEF, 9/2005
• http//indico.cern.ch/conferenceDisplay.py?confId
  a054644
• Update at Global Alignment Mini-Workshop in
  Cambridge, 1/2006
• http//indico.cern.ch/conferenceDisplay.py?confId
  a058473
• LOOKED AT
• Occupancies in IT
• Selection of good sample of tracks high
  quality, isolated, etc.
• Seeding (Tsa)
• - Works fine without B-field
• - But these conclusions were done with an
  IT-only Tsa algorithm
• - Need to check with present code should be
  OK
• Matching -gt sample of Long tracks
• Estimation of momentum (matching to muon stations
  or calorimeter)
• - Matching to CALO clusters doable with
  TrackCaloMatch
• Fitting these tracks

7
What we know so far (2/3)
8
What we know so far (3/3)

• Conclusion - minimalistic set for tracking
• PATTERN RECOGNITION
• Velo tracking
• Seeding
• Long tracking matching (maybe also forward
  tracking?)
• Matching with muons
• FITTING
• Standard Kalman filter with special options for
  straight tracks
• - pretty much like options used to fit
  Velo tracks
• OTHER
• Set of dedicated tools
• - e.g. TrackCaloMath
• What else?

9
Open Discussion

• HOW TO PROCEED?
• AVOID OVERLAP OF WORK
• AND MAKE SURE THE VARIOUS INTERVENIENTS
  COOPERATE
• - I havent seen much communication between
  trackers and aligners so far ?
• WHO DOES WHAT? VOLUNTEERS?
• WE SHOULD ALLOW US SOME STUDY TIME
• AND SUMMARISE THE CONCLUSIONS AND DEVELOPMENTS
  AT OUR NEXT WORKSHOP