[Halld-offline] Offline Software Meeting Minutes, April 30, 2014

Thu May 1 17:16:34 EDT 2014

Folks,

Please find the minutes below and at

https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_April_30,_2014#Minutes 
.

   -- Mark
_____________________________________________

GlueX Offline Meeting, April 30, 2014
Minutes

    Present:
      * CMU: Will Levine, Paul Mattione, Curtis Meyer, Reinhard Schumacher
      * FSU: Aristeidis Tsaris
      * IU: Matt Shepherd
      * JLab: Mark Ito (chair), David Lawrence, Mike Staib, Simon Taylor,
        Beni Zihlmann
      * NU: Sean Dobbs

Announcements

     1. Dmitry's visit is over. He is still reachable via email and is
        happy to answer questions.
     2. The nightly build running with using SCons for the build. David has
        a [33]wiki page describing the system. Note that the environment
        for using these builds is different than that which worked for the
        BMS make system. Both the b1pi and the single-track tests are now
        working with the new scheme. Mark will use this for the next tagged
        release.
     3. Beni has successfully built the GlueX software suite on an Ubuntu
        14.04 box.
     4. David has successfully built JANA on a Raspberry Pi board.

Review of minutes from the last meeting

    We reviewed the [34]minutes from the April 16 meeting.
      * Paul clarified that currently, kinematic fits are done using the
        thrown value of the beam photon energy.
      * Mark clarified that at present the online group is using the
        one-and-only GlueX Subversion repository.
      * David gave the wiki software update a go. We will wait for an
        [35]upgrade of the web server before trying it again.

Data Challenge

Even Tally Board

    We looked at the [36]Event Tally Board. We are at 6.6 billion events.
    Running continues on the OSG.

Site Status Updates

      * At JLab:
           + Doing clean-up of missing jobs.
           + Archiving hd_root files to tape. This was not done during the
             running of the jobs.
           + Mark has been using the SRM successfully. There remains a
             problem with some of the SRM servers at UConn not being
             white-listed by the JLab firewall in the initial network
             set-up some years ago. We also realized that this means that
             NU is not white-listed at all.
      * All of the CMU-generated data has been uploaded to NU.
      * On the OSG:
           + Over the past few days there was a problem with SRM transfers
             not succeeding on the OSG. This was due to incompatible SRM
             client on remote nodes. Now Richard including our SRM client
             with the remote jobs to insure compatibility, and will start
             up submitting jobs again.
           + The OSG will start mixing in some 9002 and 9003 running.
           + Richard will continue until we get a solid stretch of
             full-capacity running. After that he will shut it down at his
             discretion.

DC-3 Planning

    Mark mentioned two topics that we need to address before the next data
    challenge:

Raw data generation and reconstruction capability

    David will give a report on status at the next meeting. There is still
    some work to do on the calibration layer, e. g., converting raw ADC
    values to energy. Sean has been looking at this recently.

Generating electromagnetic background more efficiently

    David had started work on a scheme for mixing in pure electromagnetic
    background events in with events of interest. There are several
    questions:
     1. Is this the right scheme? (Likely yes.)
     2. How big does the EM background library have to be?
     3. How much realism is needed in combining background hits with
        physics event hits?
     4. Do we wait for Geant4 before working on this in earnest?

    We agreed to have David present the status of his work at a future
    meeting and use that as a starting point for discussion.

Event Skimming

PID & Skim Cuts Update

    Paul presented updated results on his skim studies focusing on \gamma
    p\to \pi^+\pi^+\pi^-(n) . See his [37]wiki page for details. An
    [38]earlier stage of this work was presented at the [39]last Physics
    Meeting. Some items from the presentation and discussion:
      * The PID combined PID confidence-level cut seems to cost a lot in
        terms of efficiency. This cut is on the combined CL of
        time-of-flight measurements for all tracks. These measurements may
        come from the TOF, the Start Counter, the BCAL, FCAL, or the
        tracking chambers.
      * Some of these measurements look biased and/or non-Gaussian, some
        with puzzling features in the distributions.
      * Matt suggested looking a lower level quantities to do the skims,
        such as charged track multiplicity or total energy.
      * Paul told us that the number of tracks was generally pretty high,
        even for these 3pi events and for this study the requirement was a
        minimum of 3 charged particles (++-) with no upper bound. And the
        neutral shower count can be high as well. That makes event
        classification by topology difficult. We agreed that the situation
        would be a lot better if this could be done more reliably and that
        it was worth looking into.

BCAL Timing

    Will has studied the timing distributions used in the PID cut for the
    BCAL. See [40]his slides for details.

    He sees a long tail going to late times, out to several nanoseconds,
    for pions but not for photons. He tried using a truncated mean of hits
    contributing to the cluster, using only the earliest 50% by time. This
    did cut down on the tail, but introduces a bias to early times as might
    be expected. He looked at correlations of the late tail with other
    cluster properties, but did find any strong ones.

    Matt suggested trying the study with muons to see what happens.

Update on EventStore Indices

    Sean presented an update on his EventStore development. See [41]his
    slides for details.

    During Sean's presentation, Mark finally came to the understanding that
    the framework is essentially a system for managing event lists based on
    a common complete or nearly-complete set of events contained in a
    well-defined set of files. Various skims are then realized as event
    lists on that data set. The value added is mainly in that users can
    easily access multiple skims performed by the collaboration or
    individuals since there is only one set of data files. The event
    analyzer, JANA in our case, need only be instrumented to access and
    select events based on the lists. The data itself needs no special
    hooks or modification. In addition, there can be multiple target data
    sets, either from different run periods or or from higher level
    processing passes on a single set. These choices are available and
    documented within the framework. At least that is his understanding.

Other Agenda Items

    We deferred the following to a future meeting.
      * Tagger Reconstruction
      * Smooth exit from reconstruction errors
      * Git, Github, Halls A, B, C
      * C++-11

References

   33. https://halldweb1.jlab.org/wiki/index.php/SCons_Build_System
   34. 
https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_April_16,_2014#Minutes
   35. 
https://mailman.jlab.org/pipermail/gluex-collaboration/2014-April/003749.html
   36. 
https://docs.google.com/spreadsheets/d/1qvF9B-76gr8NdsTKsO17jqL0qc5OXqK46JluvXnJ98k/edit?usp=sharing
   37. https://halldweb1.jlab.org/wiki/index.php/Mattione_Update_04302014
   38. https://halldweb1.jlab.org/wiki/index.php/Mattione_Update_04212014
   39. 
https://halldweb1.jlab.org/wiki/index.php/April_21,_2014,_Physics_Working_Group
   40. 
https://halldweb1.jlab.org/wiki/images/6/62/Bcal_timing.20140430_offline_meeting.pdf
   41. 
https://halldweb1.jlab.org/wiki/images/1/18/GlueX_Offline_ES_043014.pdf

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