BCAL Reconstruction Meeting 2015-09-17

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Video Conferencing Information

Meeting Time: 11:15 a.m. EDT

  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
    • US or Canada: +1 888 240 2560
  4. Upon connection all microphones are automatically muted. To unmute your mike on a Polycom or equivalent unit, enter *4. Unmuting on a computer is trivial as there is a microphone button than can be clicked.
  5. More information on connecting to bluejeans is available.

Participant Direct Lines

  • JLab Phone: in CC F326 is 757-269-6460 (usual room)
  • JLab Phone in CC L207 is 757-269-7084
  • Phone in the Regina Video-conference Suite is 306-585-4204


  1. BCAL Reconstruction Issues
  2. BCAL Reconstruction Algorithms
  3. Will's reconstructed energy info

Action Items

  1. F250 discussion: peak value into higher level objects (Mark, Mike)
  2. Make MC plots that show E vs Egen and resolution (Tegan)
  3. Low priority items
    1. z-coordinate determination from up/down amplitude ratio
    2. Sampling fraction tables (Tegan, Andrei)
    3. Code Cleanup


  1. Announcements
  2. Action Items
  3. Commissioning Efforts
    1. Effective Speed of Light (George)
    2. Time-walk corrections (Noemi)
    3. Layer efficiencies (Ahmed)
    4. Up/down gain ratios for spring data (Mark)
    5. Muon decays (Will)
  4. Reconstruction
    1. Eta reconstruction (Tegan)
    2. Single-ended energy summary (Will M)
  5. Simulations
    1. CPPsim (Tegan)
    2. Cosmics runs & simulations with B-field on (Andrei)
  6. Any other business


Attendees: Elton, David, Simon (JLab), Mike, Will M. (CMU), Christina, George (Athens), Andrei, Ahmed, Noemi, Tegan, Zisis (Regina)’’

  1. Announcements: Formal approval to proceed with magnet repairs is pending: there was an external review committee and Patricia has tasked them to respond. The magnet is cold now but warming up and will be opened today or tomorrow. Magnetic field could be available at the earliest in mid December. There are things to be done w/o magnetic field and we may establish standby shifts in December to be manned by folks nearby or at JLab. This will be decided at collaboration meeting.
  2. Action Items
  3. F250 discussion: Mike reported that he entered the peak value into the DigiHits and Hits objects and has asked Mark to have a look at it and do a "pull" into github.
  4. Make MC plots that show E vs Egen and resolution (Tegan): Will search for those plots and upload them for next week's Calorimetry meeting.
  5. Low priority items
    1. z-coordinate determination from up/down amplitude ratio
    2. Sampling fraction tables (Tegan, Andrei): discussion has resumed on this with the goal of implementing it this fall.
  6. Commissioning Efforts
    1. Effective Speed of Light (George): nothing new on effective speed; working on finishing the z-coordinates. George sent a request to Mark to pull the ccdb constants into github.
    2. Time-walk corrections (Noemi): working with Mike's plugin and making changes following Andrei's input.
    3. Layer efficiencies (Ahmed): peak-pulse-threshold script to cut out low amplitude pulses is giving unexpected behaviour. Ahmed is investigating. A draft layer efficiency report has been given to Zisis for feedback and will become available on DocDB next week.
    4. Up/down gain ratios for spring data (Mark): Elton reported on Mark's behalf. Mark looked at up/down ratios from the spring data; see log entry 3351521 and followup entries 3351612 and 3351615. Recall that comics data was used from last fall for up/dn gain and these were implemented for the pi0 minimization. Mark is updating the procedure to make it a routine calibration during online data taking. It is more user friendly: Mark wrote a plugin. Gain ratios shown for Module 6 are the worst case; most other modules look ok. Run 3185 has shadow background at low z high ratio, and the reverse. Background origin and shape not understood yet. Cuts were very loose; negative hits are still in. Perhaps tighter cuts will help. AS: how was peak found? ES: from timing used ADC values, t-w should be small. Will M: new AttenLen are not in the ccdb cause Mark is investigating things and will implement the new numbers later on to see their effect. Folks should use their local ccdb.
    5. Muon decays (Will)
      • Michel Spectrum
      • Michel Reconstruction issue (Will M)
      • Michel spectrum expectation: average is 37MeV, peak 53MeV. Data Electron spectrum puzzling as it is about half of what is expected. Spectrum from data does not look as expected: it is off by a factor of 2 and peaks at the wrong place. Ideas folks? Andrei suggested that we might be simply plotting minimum ionizing spectra, but unclear why all the electron energy is not reflected there.
  7. Fire drill at UofR; Regina disconnected for 10 min.
  8. Reconstruction
    1. Simon did a survey of multi photon final states with a tag photon and no other tracks. eta->3pi0 (6 gamma) shows clearly in spectrum. Eta prime might be there too. NIM paper from RadPhi shows 6gamma but no eta-prime. The eta-prime decay of interest here is pi0pi0eta which has a 22% BR. Other decays to look at in the future are: rho-0 gamma (29%), pi+pi-eta (43%) omega gamma (3%) gamma-gamma (2%).
    2. Eta reconstruction (Tegan): Tegan retraced Justin’s steps: suggested cuts for spring data using DReaction class. One charged track only. Then used same plugin over the 6 data runs (3 amorphous, 3 diamond runs), summed up in this plot; will look at differences. Deltat_RF Picks from same RF bunch; predefined in DReaction. It can be the proton hitting the start counter or something else. Tegan was asked to fit data and get peak, width of eta. Right after the meeting, he emailed the eta fit and later on the fit broken down into amorphous and diamond runs.
    3. Single-ended energy summary (Will M) Will gave a summary of including single-ended hits into the energy distribution. The effect is to increase the mass by 4 MeV and reduce the width by 0.2-0.4 MeV. Remove from agenda. We’re done on this topic.
      • The database update will wait till the new atten and up/down gain ratios can also be included.
  9. Simulations
    1. CPPsim (Tegan): Richard was adding CDC hits to G4 sim.
    2. Cosmics runs & simulations with B-field on (Andrei): Checked time of runs taken to see when bad runs occurred (email to Elton and Mark). Good runs Dec 8-9, problem runs started around April 15 and continued for some time into May. Good runs have external triggers in ROC, bad runs not top but only channel 5 (1-4 missing). Channel 5 counts firing more frequently. Andrei: nth in logbook. Any paper logbooks in April? Answer is David’s automated RunInfo v1 script. Run conditions are also available.
  10. Any other business: none