July 13, 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.
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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
    1. Classifying FCAL Showers (Rebecca Barsotti)
  5. BCAL update
  6. Calibrations
  7. Reconstruction and Simulation
    1. 2017 mcsmear Workplan
  8. NIM articles
  9. Any other business


Attendees: Elton, Mark (JLab); Zisis, Ahmed, Tegan (UofR); Sean (NW); Christina, George (Athens); Matt, Joe, Rebecca Barsotti (IU), Will (CMU)

  1. Announcements
    • Accelerator expects startup on Sep 28 and start to deliver beam to experimental halls during the first week of October.
  2. Action Items
  3. Activities during the down
    • Sasha will start working on the trigger and will turn on selective parts of the Fcal and Bcal to support the studies.
  4. FCAL Update
    1. General updates (Matt)
      • Adesh has moved to Florida and there are several loose ends that need to be picked up
      • Repeating calibration with correct block size
      • Use photons with a narrow energy range
      • Understand the puzzle related to the fact that the measured Fcal energy does not improve with energy. This could in part be due to poor background representation.
      • Add dead channels into the MC. Jared is using the LED data to investigate problematic channels
    2. Timing studies
      • Joe is using the LED data to check time walk, which should be absent in the FADC data. Investigate with LED data with varying intensity
      • Matt is using the sample of clean omegas to check various timing aspects. Looking at timing between particles and the event time. Investigate the optimal time for a cluster. For example the energy average time might be better than the time of the largest block, which is currently being used.
    3. Classifying FCAL Showers (Rebecca Barsotti)
      • Investigation to understand whether one might be able to distinguish clean electromagnetic showers from other energy depositions in the calorimeter not associated with charged tracks.
      • Use clean sample of gp->pw, w->pi+pi-pi0
      • Classify showers in to 0) showers from pi0 decays 1) showers with matched charged tracks 2) other
      • Use machine learning techniques to distinguish type 0 from type 2 showers.
      • Preliminary results of various algorithms presented
      • Elton: Evaluate use of discriminating measurements such as energy, which would be kinematic dependent. Matt: Might wish to re-evaluate inputs to the learning algorithms
      • Mark: Do you have a planned test phase? Matt: Idea is to store the classifier along with the data so that it could be used as a cut variable. Classifier needs raw data for its determination. If the classifier is stored in the output, this could be used as a test with other exclusive reactions.
      • Will: Have you looked at neutral split-offs from good pi0 showers? Matt: This has not been looked at in this context. It is most important related to the efficiency, which Jon Zarling is focusing on
  5. BCAL update
    1. Noise Study (Ahmed)
      • Data were taken with a range of bias and temperature settings to study the mean and pedestal widths vs. over voltage.
      • Goal is to repeat study by Mark a couple of years back.
      • Program is running but bugs are still being found. Progress at the next meeting
    2. Photon efficiency.
      • Zisis reported that Tegan is finding that the ratio (eta->3pi0)/(eta->pi+pi-pi0) corrected for branching ratios is about 0.3. This could be interpreted as a single photon efficiency of about 0.75.
      • Will: Does not have enough experience to judge whether this is reasonable.
      • Matt: What is the probability of missing 1 photon due to either geometry or a threshold? This could be a large contributor to the overall efficiency.
      • Matt: For the Fcal, the efficiency for single photons is of other 95% for showers greater than about 0.5 GeV.
  6. Calibrations
  7. Reconstruction and Simulation
    1. 2017 mcsmear Workplan
      • Mark: Investigating options for using etas to check energy resolution, since the mass width is dominated by energy. (The pi0 width has important contributions from position as well as energy resolution).
      • Matt: Could this sample also be used for the FCal? Mark: Yes. Need to find the optimum way of studying the systematics of energy resolution, perhaps selecting decays with photons of similar energies. Need also to understand decays that are solely in one detector, but mixed events can also increase the data size.
    2. Charged Clusterizer (Will)
      • See Log Entry
      • Has been working on MC generated muons and pions and investigating how the charged particle clusterizer deals with them. Updated the log entry and comments are welcome.
      • Also using pions from Matt's sample of exclusive omegas.
      • Expect to have a report at the next meeting.
      • Using the skim sample of pi+pi-eta from 2016 to study energy resolution with etas
    3. Sean
      • What is important is to be comparing data with MC and to use physics to identify issues to keep focus on issues that are important to completing projects.
  8. NIM articles
    • Zisis has update the draft with improved figures for some of the simulation sections. Root scripts are being saved that produce the figures, so that updates and small changes can be easily made. References have been updated, etc.
    • Elton will work on this today and tomorrow and push updates to git by the end of the day.
  9. Any other business
    • George is working on a physics analysis in the 2pi and 2pi-eta final state. This channel is interesting due to some expected hybrid decays -> f(1270) eta -> 2pi eta.