GlueX Offline Meeting, April 4, 2012

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GlueX Offline Software Meeting
Wednesday, April 4, 2012
1:30 pm EDT
JLab: CEBAF Center, F326/327


  1. Announcements
  2. Review of minutes from the last meeting: all
  3. Reconstruction sub-group reports
    1. Calorimeters
    2. Tracking
      1. Improvements in tracking residuals due to recent changes
      2. Kinematic fitting of ρ and b1π events
    3. PID Reconstructed TOF, β (Mattione)
  4. Offline Software Review Planning
  5. New JANA release
  6. Action Item Review
  7. Review of recent repository activity: all

Communication Information

Video Conferencing


Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2012-2Q on the JLab CUE. This directory is accessible from the web at .


Attendees: David L.(chair), Simon T., Beni Z., Matt S., Kei M., Nathan S., Paul M., Will L.


  • Elliott: TDR will be reorganized a bit at the top level to better fit the function of the document.
  • PWA school at W&M: 3 weeks
  • GEANT4: 1 week school presented by GEANT4 authors (3 SLAC, 1 LHC) July 7-13

Calorimeters (Will)

Still places in code that refer to rad hard glass in FCAL. It has been fixed. Affect at low angles. Improves resolutions a bit (as expected). Also slightly better efficiency.

Tracking (Simon)

  • FDC 4th package now 20 cm closer
  • Material maps modified to include more precomputed values (MULS related)
  • Tracking chi-sq still seems pretty flat with large spike at zero (0.1-6.1 GeV/c pions)
  • Tracking parameter residual plots look good overall with errors still off for very forward going tracks
    • Material map improvements have helped
  • Backward angles still problematic regarding residuals and errors
  • Looked at pi+pi- events from rho decay.
    • CL from kinematic fit looks very good, but still has spike at zero
    • Found paper Simon thinks may have been basis for our CLAS-inherited kinematic fitter
    • Assumed pi0 missing mass (did not use reconstructed photons)
    • Fitter only uses px,py,pz parameters in fit (does not fit position parameters)
    • Also did a set of b1pi events. (CL also looks good)

PID (Paul)

  • Igor noticed problems with reconstructed beta (Paul saw similar issues)
  • TOF hits are rarely reconstructed due to tiny energy deposition.
  • Beni suggested low energy hits are backsplash from calorimeter
    • Paul: That may be, but there are hardly any hits from TOF
  • Matt noted that a 2007 MC study he did had a MIP peak closer to what is expected (few MeV)
  • FCAL timing is slightly off (known issue).
    • Causes beta to be systematically off.
  • BCAL beta has problems because of reconstructed start time of event.

Offline Software Review Planning (David)

Two slides were prepared for a multi-hall Software Review Preparations meeting on Tuesday next week. One deals with "Tight Spots and Weaknesses" and the other outlines our Management Plan.

Elliott emphasized the likelihood of manpower being drained for the online activities in the tight spots slide.

New JANA release (David)

  • A new JANA release is out (version 0.6.4)
  • Several bug fixes and feature enhancements (no fundamental changes to core functions)
  • Xerces 3 support is available in the new version.
    • Simon noted that HDDS still does not compile against xerces 3
    • David noted that this is due to "read only" nodes being added in version 3. It's not clear at this point whether the problem is easily fixed, or requires a major rewrite.
    • Richard should be contacted to see if he can have a look.


  • We looked briefly at the Mantis tracker system.
  • Everyone was encouraged to review their tasks periodically and to assign unassigned tasks as appropriate.