GlueX Offline Meeting, March 21, 2012

From GlueXWiki
Jump to: navigation, search

GlueX Offline Software Meeting
Wednesday, March 7, 2012
1:30 pm EDT
JLab: CEBAF Center, F326


  1. Announcements
    1. New release: sim-recon-2012-03-12: Mark
  2. Review of minutes from the last meeting: all
  3. Reconstruction sub-group reports
    1. Calorimeters: FCAL_Reconstruction_in_b1pi_events_03/14/2012: Will
    2. Tracking
    3. PID
  4. Kinematic Fitting Documentation
  5. Offline Software Review Planning
  6. Action Item Review
  7. Review of recent repository activity: all

Communication Information

Video Conferencing


  • To connect by telephone:
    1. dial:
    2. enter access code followed by the # sign: 3421244#
  • Chairman's cell-phone: (757)768-2364


Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2012-1Q on the JLab CUE. This directory is accessible from the web at .



  • CMU: Will Levine, Paul Mattione, Curtis Meyer
  • FSU: Nathan Sparks
  • IU: Ryan Mitchell, Matt Shepherd
  • JLab: Mark Ito (chair), David Lawrence, Simon Taylor, Elliott Wolin, Beni Zihlmann
  • UConn: Richard Jones


  • Mark announced that sim-recon-2012-03-12 has been released. See the sim-recon release page for details.
  • Beni announced that he, in consultation with Richard, implemented a change to allow secondary vertices to be stored in the HDGeant output. The resulting particles will not appear in the list of generated particles.

Review of Minutes from Last Meeting

We reviewed the minutes from the March 7th meeting.

  • Paul has checked in the two changes to the FCAL cluster finding that Will discussed last time:
    1. allow a charged track to veto more that one cluster
    2. increase the charged-track-cluster match radius
  • Paul's restructured classes are part of the sim-recon-2012-03-12 release.

Reconstruction Sub-Group Reports


Will reported on further work on FCAL photon reconstruction. See his wiki page for plots and details (new results start in the "energy resolution" section.

  • He has measured energy resolution and offsets from generated values as a function of photon energy for all "unconverted" photons (those that enter the FCAL as a photon) and for the entire population.
  • He looked at the effect on reconstruction efficiency when single-block clusters are allowed. Efficiency below 400 MeV improves significantly.
    • We encouraged him to make the change to allow these clusters. Users can always cut them later if the sample is too contaminated for their purposes.
  • Paul proposed that timing cuts Will discussed last time be included in the standard b1pi analysis that is run twice a week.
  • Not all issues have been resolved. Will will continue his work.


Simon has started at kinematic fitting code, in particular addressing errors reported by tracking. He uses pπ+π- events where the pions come from a ρ. The pulls for px, py, and pz for the pions are too large by 20 to 25%, for the proton, too large by about 10%. Also the efficiency for getting a successful fit is poor.

He has started looking at how use of the material map is implemented. The map comes in through the calibration system and there is averaging done in spatial bins to improve performance. Simon will do a comparison with finer bins to see if there is any improvement.


Paul has gone back to working on tracking, picking up the spiraling pion problem again. He has it so it will link hits together on spirals, though there is still some work left to do. He still gets many possibilities for track candidates.

Kinematic Fitting Documentation

Will re-discovered the wiki page on kinematic fitting and is updating the information and working on new, functional examples.

Offline Software Review Planning

David reminded us of the wiki page where he has gathered material relevant to the review.

Areas of current work:

  • refinement of the schedule
  • a one-pager on a software management plan
  • a list of "tight spots and weaknesses"
  • a research management plan
    • Hall A provided an example. Names are assigned to projects.

So far, estimates of manpower required seem to match expectations from collaboration on the FTE's available.

Elliott asked if the algorithm for the level 3 trigger on on list of things to be reviewed. It is not at present.

The JANA/CLARA thing continues to be raised in the context of cross-Hall cooperation. Different people have different ideas on how this should go.

New Action Item

  • Include Will's new photon timing cuts in the standard b1pi analysis.