Jun 29, 2017 Calorimeter

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Video Conferencing Information

Meeting Time: 11:00 a.m.

  1. To join via a Web Browser, go to the page [1] https://bluejeans.com/907185247.
  2. To join via Polycom room system go to the IP Address: (bjn.vc) and enter the meeting ID: 907185247.
  3. To join via phone, use one of the following numbers and the Conference ID: 907185247.
    • US or Canada: +1 408 740 7256 or
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Participant Direct Lines

  • JLab Phone in CC L207 is 757-269-7084 (usual room)
  • JLab Phone: in CC F326 is 757-269-6460
  • Phone in the Regina Video-conference Suite is 306-585-4204
  • Athens Phone: in Christina's office is 011-30-210-727-6947

Action Items

  1. Decide on procedure to calibrate 4ns offsets during the next run.
  2. Check in the code, including scripts, that is used for recent calibrations into git (BCAL: Mark, FCAL:Adesh)


  1. FCAL HDFCAL log book
  2. BCAL HDBCAL log book

Tentative Agenda

  1. Announcements
  2. Action Items
  3. Activities during the down
  4. FCAL Update
  5. BCAL update
  6. Calibrations
  7. Reconstruction and Simulation
    1. 2017 mcsmear Workplan
  8. NIM articles
    1. BCAL
      • Document updates (Elton). Thanks to George and Will for providing text on veff and gains. Thanks to Mark and Andrei on providing plots.
      • Still to do : Shower (clusterizer) reconstruction (Will), performance (all)
  9. Any other business


Attendees: Elton, Mark, Adesh (JLab); Matt, Jon (IU); Zisis, Tegan, Ahmed, Andrei (UofR); Christina, George (Athens); Will, Curtis (CMU).

  1. Announcements
    1. Hall B solenoid arrived at JLab on Tuesday and has been craned onto the beam line. It is the last piece of the 12 GeV project.
    2. Adesh - last meeting, will be leaving to take a data scientist position in Florida. IU has opened a replacement position and is interviewing candidates.
  2. Action Items
    1. Accidentally passed over during meeting. Will revisit next time.
  3. Activities during the down
    1. None.
  4. FCAL Update
    1. Calibrations (Adesh)
      • Timing issues, reported previously, have been fixed.
      • Working on updating the geometry to incorporate the correct block size. First, changes to geometry will be made in sim-recon and new calibrations completed. These will be checked before moving to the second stage, when the geometry will be ported to xml files.
      • "How to" document for FCAL is being written. This will describe how to operate FCAL, perform the hot checkout, find and fix problems prior to a data run, monitor bases, coordinate fixes with Chris and Nick, Hovanes before turn on.
      • Leave documentation on how to move skim files to IU.
      • These documents will be made available to Adesh' successor.
    2. Summer projects at IU (Matt)
      • Wrote a plugin to select exclusive omega events. Selection has a 5% CL cut to obtain a very clean sample and relatively small event skim.
      • Most omegas are in the FCAL, but that is not a requirement. They may be useful to BCAL, or other projects.
      • REU Student is using this sample to identify showers in the FCAL that match tracks or pi0 decay (true photons) or "other". Use the samples of "true" and "other" with machine learning tools to classify showers as true photons.
      • Timing resolution. Recall Adesh found a low-energy "fast" tail. Using photons from pi0 decays, Matt finds Gaussian timing (sigma=280 ps) and no tail. When checking the timing with pi+ and pi- tracks, a low energy "fast" tail develops with about 1 ns lag. Speculation is that this tail is due to non-interacting pions which arrive at the pmt faster than large-angle photons from shower.
      • Zisis: What is the minor peak on the pi0 sample? Unclear, possibly fluctuations.
      • Mark: How may omegas end up in the BCAL? Have not studied in detail. Jon: possibly up to 20% with angles < 30 deg.
      • LED runs. Investigating stability of signals over the run. See some instabilities at this preliminary stage, and will investigate.
  5. BCAL update
    1. Log Entry 3477009 (Ahmed).
      • Posted a log entry on anomalies seen in the LED monitoring data from spring
      • No progress on analyzing the LED data that Tegan took when he as a JLab in May.
  6. Calibrations
    1. Submitted a pull request for a skim file with exclusive pi+pi-pi0 (no constraint on omega) to investigate gain calibrations (Tegan)
      • Use loose cuts on missing energy, mass. No kinematic fit required
      • Matt: What is the size of the output? (For the exclusive omega sample above with CL > 5%, is needed to reduce the data size by x30. Tegan will investigate.
  7. Reconstruction and Simulation
    1. 2017 mcsmear Workplan
      • Sean has laid out a plan for each subgroup to work on aspects of comparison between data and MC.
      • Mark is looking at most data/MC comparisons for the BCAL already.
      • Elton: Experimentally measuring single-photon resolutions in our detector is difficult due to poor missing mass resolution
      • Mark: Time resolution, measured relative to the RF signal is accessible experimentally. For the present data, measured data resolution decreases with energy as expected. The MC shows a very flat timing resolution as a function of energy. However, MC has not been calibrated in the same way as the data, so this could account for some of the differences.
      • Curtis: One should also look at width of reconstructed omega -> pi0 gamma
      • Matt has filled in the table with identified persons for all tasks, but work may extend beyond the summer.
  1. NIM articles
    1. BCAL
      • Document updates (Elton). Thanks to George and Will for providing text on veff and gains. Thanks to Mark and Andrei on providing plots.
      • Still to do : Shower (clusterizer) reconstruction (Will), performance (all)
      • Zisis and Elton and handling additions to the draft. Please send them any updates. Zisis will be updating the document over the next week.
  2. Any other business