GlueX Offline Meeting, August 24, 2011
GlueX Offline Software Meeting
Wednesday, August 24, 2011
1:30 pm EDT
JLab: CEBAF Center F326
Agenda
See Curtis's email for some background.
- Announcements
- Review of minutes from the last meeting: all
- Proposal to shrink the DST Data Format size (Richard/Discussion).
- Tracking chi-squared/error update: Paul Mattione.
- Tracking dE/dx update.
- FCal reconstruction update.
- BCAL reconstruction 8/24/11
- FDC Changes in GSIM[1] and restoration of default behavior [2].
- Default behavior (same as old): only the time at the doca is reported (no explicit cluster generation).
- Drift times and diffusion computed based on results of Garfield simulations for nominal gas mixtures for FDC and CDC.
- Treatment of magnetic field maps in the CCDB: Dmitry
- Action Item Review: all
- Review of recent repository activity: all
Communication Information
Telephone
To connect by telephone:
- dial:
- US and Canada: (866)740-1260 (toll free)
- International: (303)248-0285 (toll call) or look up toll-free number at http://www.readytalk.com/intl
- enter access code followed by the # sign: 3421244#
Video Conferencing
- ESNet: 8542553
- EVO:
- Meeting URL: http://evo.caltech.edu/evoNext/koala.jnlp?meeting=292I2iMeMB929nDs9aD9
- Phone Bridge ID: 10 1789
Slides
Talks can be deposited in the directory /group/halld/www/halldweb1/html/talks/2011-3Q
on the JLab CUE. This directory is accessible from the web at https://halldweb1.jlab.org/talks/2011-3Q/ . You have to be a member of the "halld" Unix group to do this.
Minutes
Present:
CMU: Will Levine, Paul Mattione IU: Kei Moriya, Matt Shepherd JLab: David Lawrence, Mark Ito (chair), Dmitry Romanov, Sascha Somov, Simon Taylor, Elliott Wolin, Beni Zihlmann UConn: Richard Jones
Announcements
Elliott will update the "DANA-EVIO stuff" now that the reconstruction class re-arrangement has settled down.
Review of minutes from the last meeting
We reviewed the minutes from the ??? meeting.
- Elliott wondered if using an ??? was overkill for the online since the queries are so simple.
- Paul asked for collective wisdom about deleting DPhoton from the trunk. He will delete it.
Proposal to shrink the DST data format size
Richard objected to the title of this agenda item. Nonetheless...
He walked us through the [??? recently circulated spreadsheet] detailing the contents of the proposed DST and the anticipated savings in space for each reconstructed C++ class. The idea is to save enough information to reconstitute the targeted DANA classes minimizing the information while keeping the classes useful for data analysis.
Some random notes:
- The particle list cuts only di-quarks from those generated by PYTHIA
- A compression scheme is possible and there were several proposals on how to do it.
- The exact format of the serialized data is yet to be determined.
Tracking chi-squared/error update
Paul led a discussion of his wiki page. We discussed his proposal, to have a formal framework for calculating and storing hit-by-hit measurement errors and then propagate them forward to get sensible errors on particle kinematics. Several of us thought that concentrating on high-level kinematic quantities (e. g. energy of a cluster, angle of a track), post-reconstruction might be more fruitful.
Tracking dE/dx update
Simon led us through his wiki page. Executive summary:
- units problem
- fixed now
FCAL reconstruction update
Beni had previously reported a surplus of split clusters in the FCAL, but on closer examination they turned out to be from photon conversions upstream of the FCAL producing separate, legitimate clusters. The reconstruction is behaving as expected.
BCAL reconstruction update
Will led us through his wiki page describing recent work understanding photons detected in the BCAL. His summary is reproduced here:
- BCAL reconstruction seemed to be an obstacle in b1pi events
- Two reconstruction algorithms in tree: KLOE algorithm=default, "new" algorithm by matt s.
- Found two issues which lead to poor energy resolution at low E (fixes not checked in yet)
- "New" algorithm seems to be doing well for single-photon events
- Further study of b1pi, etc.
- Further fine-tuning needed, but maybe should wait until BCAL segmentation finalized?
Note that this is work in progress.