[Halld-offline] Offline Software Meeting Minutes, September 4, 2013

[Mark M. Ito]

Colleagues,

Please find the minutes below and at

https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_September_4,_2013#Minutes 
.

   -- Mark
______________________________________________________

GlueX Offline Meeting, September 4, 2013
Minutes

    Present:
      * CMU: Will Levine, Paul Mattione, Curtis Meyer
      * IU: Kei Moriya, Matt Shepherd
      * JLab: Mark Dalton, David Lawrence, Mark Ito (chair), Simon Taylor,
        Elliott Wolin
      * MIT: Justin Stevens
      * Northwestern: Sean Dobbs
      * UConn: Alex Barnes

Review of Minutes from Last Meeting

    We looked at the [25]minutes from the August 21st meeting. No major
    comments.

Report from Work Flow Meeting

    Mark reported that last week there was another meeting of this
    committee. Mainly it was information gathering by Scientific Computing
    staff. They had questions about what practices for work flow management
    are being used or planned for Halls B and D. There will be another
    meeting in three weeks.

CDC Track Finding

    Paul has done an almost complete rewrite of the CDC track finding code
    in order to support the goal of elimination of ghost tracks from
    curling tracks in the CDC. That having been said, the resulting code
    can be used for all tracks with all or part of their hits in CDC. He
    gave a detailed description of the ideas and some comparative studies
    of the results (existing code vs. his new "spiral" code). See [26]his
    wiki page for his presentation. Some highlights:
      * The new code finds clusters of hits ("super-layer seeds") in both
        axial and stereo layers. The existing code only does so for the
        axial layers.
      * Tracks are found from the inner super layers to outer, using stereo
        layers and always adding hits from a complete seed.
      * Note is made of seeds that are consistent with a track that is at
        the outside of a curling track. These have a pattern that is
        roughly aligned with consecutive straws in a layer rather than
        roughly along a radial line in the CDC. This information is used
        later to distinguish between track candidates that are actually
        pieces of the same curling track.
      * He has studied performance for single tracks and for a variety of
        physics topologies.
      * He has developed a new plug-in that refines the efficiency
        calculation used in the bi-weekly single-track reconstruction
        tests. The new method requires that a found candidate or time-based
        track agree with the generated parameters to be considered found.
      * Overall he sees improvement in track finding efficiency, especially
        at low momentum at polar angles greater than about 30 degrees.
        Improvements can be a large as 10% in (e[new]-e[old]e[old]. Places
        where efficiency is degraded are few (if there are any at all).
      * In many cases, although track finding efficiency is improved
        relative to the existing code, the existing code recovers some
        efficiency at the track fitting stage (using the Kalman fitter).

    Again interested parties should look at [27]his wiki page to get the
    details and quantitative characterization of the improvements.

    Retrieved from
"https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_September_4,_2013"

References

   25. 
https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_August_21,_2013#Minutes
   26. https://halldweb1.jlab.org/wiki/index.php/Mattione_Update_09042013
   27. https://halldweb1.jlab.org/wiki/index.php/Mattione_Update_09042013

-- 
Mark M. Ito, Jefferson Lab, (757)269-5295, marki at jlab.org