September 12, 2016, Analysis Working Group

From GlueXWiki
Jump to: navigation, search

Meeting Time and Place

The meeting will be on Monday September 12, 2016 at 2:00 pm EDT. For those people at Jefferson Lab, the meeting will be in room F224-225.

Meeting Connections

  1. To join via a Web Browser, go to the page [1]
  2. To join via Polycom room system go to the IP Address: ( and enter the meeting ID: 115815824.
  3. To join via phone, use one of the following numbers and the Conference ID: 115815824.
    • US or Canada: +1 408 740 7256 or
    • US or Canada: +1 888 240 2560
  4. More information on connecting to bluejeans is available.


  1. Announcements
  2. Collaboration Meeting October 6-8, 2016
  3. Reconstruction Studies
  4. AOB

Reconstruction Studies


  • Beam Polarization (Justin, Mike, Nathan)
  • Beam Energy (Nathan, Richard)
  • Flux (Justin)



  • BCAL
    • Shower Clustering (Will)
    • Neutral Energy & Efficiency (Will)
    • Hadronic Energy & Efficiency (Elton)
  • FCAL
    • Neutral Energy & Efficiency (Jon)
    • Shower Clustering (Matt)
    • Hadronic Energy & Efficiency (Matt)

Particle ID

  • SC Efficiency (Mahmoud)
  • TOF Efficiency (Beni)
  • Particle ID (All)

Channel Reconstruction, Triggering, Acceptance

  • Triggering Efficiency (Alex S., Elton)
  • ρ (Alex A., Justin) [2] [3] [4]
  • ω→3π (π0 in BCAL, FCAL, both) (Mike S.)
  • φ→2K (Alex B.)
  • Charged 4π (Alex A.) [5] [6]


  • Reconstruction, Analysis Launches
    • Alex A. reported that the first batch (post-bracket-gate) of the latest reconstruction launch over the Spring 2016 data is nearly complete. The analysis launch on this data will soon follow.
  • Collaboration meeting
    • Paul will give an overview talk on the status of the various analysis/studies topics. If you have been working on studies, please send Paul a slide or two so that he can overview your work, unless you are already giving a separate talk on the subject.
    • People interested in presenting specific physics/analysis channel talks at the collaboration meeting should notify Volker or Paul.
  • Beamline
    • Alexandre Deur has derived that the beam energy was a relatively constant ~12.05 GeV for the last run period, although fine corrections can still be made. The ~12.05 GeV energy has been set in the CCDB.
  • Tracking:
    • Mike reported that the apparent loss in associated CDC hits seen earlier by Naomi has not been effecting the track reconstruction, the bug only comes in after the fact.
    • Simon reported that the oscillating / discontinuous φ-dependence to the kinematic fitting pulls shown by Reinhard in ppbar and Mike in ω reconstruction is largely due to rotations of the CDC and FDC planes that were not taken into account in the reconstruction. These corrections were put in before the reconstruction launch.
    • Paul reported that while he has 0th-order track reconstruction efficiencies, the systematics are still rather large due to the large backgrounds. He plans to have improved results by the collaboration meeting.
    • Lubomir reported that by reconstructed tracks using only FDC hits, and then projecting back to the CDC, that he sees an offset between the two detector systems.
  • Calorimetry
    • Mark Dalton has been working on reconstructing BCAL shower covariance matrix. He will have something that can be tested soon in kinematic fitting.
    • Will reported that the BCAL preshower energies are now being reported, and are being saved in the REST files in the current reconstruction launch.
  • Particle ID
    • Beni reported that the channel-by-channel, on-board calibration of the TOF CAEN crate hardware timing will be performed once he collects a few hours of data. While this calibration can be installed on the crate, it can even be performed after-the-fact on the Spring 2016 data, slightly improving the resolution.
  • Channel Reconstruction:
    • For the p2pi channel, Alex A. compared the reconstruction results between the two different magnetic field settings (1200A, 1350A). He showed that while the overall rho yields are roughly the same for both, the slow proton is more difficult to reconstruct in the 1350A data, but the pions are better reconstructed in the "hole" region from 15 - 20 degrees. This loss in protons effectively means a reduction in low-t events at higher field, but the heavy hybrid mesons are generally favored to have higher momentum transfer, so they shouldn't be affected.
    • For the p4pi channel, Alex A. performed the same comparison. Because the protons are much faster (and more forward) in this channel, they don't have any reconstruction efficiency issues. In fact, it appears that the reconstruction efficiency is in general higher for this channel with high-field than low-field, or at least, there are more events per trigger. The cause of this is not currently understood. Hopefully, Paul's reconstruction efficiency studies will help understand what might be happening here.