Sep 7, 2017 Calorimeter

Video Conferencing Information

Meeting Time: 11:00 a.m.

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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. Check in the code, including scripts, that is used for recent calibrations into git (BCAL: Mark)
2. Add Fcal dead channels into the MC
3. Matt will send a question to Sean on how tightly the calibration constants are coupled to the software version. Matt contacted Sean and there is no direct coupling between constants and software versions.

References

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. FCAL Gains - Mike
   2. FCAL Update (Matt)
5. BCAL update
6. Calibrations
7. Reconstruction and Simulation
   1. 2017 mcsmear Workplan
8. NIM articles
9. Any other business

Minutes

Attendees: Elton, Mark, Colin Gleason (JLab); Matt, Jon (IU); Ahmed, Tegan, Andrei (UofR); Will, Mike, Curtis (CMU); Christina, George (Athens); Sean (NW).

1. Announcements
   • Colin Gleason is replacing Adesh as IU's representative at JLab. Welcome!
2. Action Items
3. Activities during the down
4. FCAL Update
   1. FCAL Gains - Mike
      • Investigating omega sample (2016) and occupancies in FCAL near beam hole
      • Finds that apparent inefficient channels are due to mis-calibration in regions where FCAL blocks were excluded from the trigger.
      • Borrowed Will's new procedure for determining BCAL gains using a histogram-fit-adjust method instead of the original bootstrap method.
      • New method shows that inner blocks can be calibrated and recovered in analysis.
      • Note that 2017 data shows similar problems
      • Matt: Need to use new method to determine accurate gains, which can be used to set new HV for the upcoming run.
   2. FCAL Update (Matt)
      • Changes to geometry and MC using Richard's help: a) steel straps around blocks, b) size of blocks, c) light tight cover, d) add light guide as sensitive region in MC
      • Changes to block spacing (4.000 -> 4.016 cm) changes reconstructed pi0 mass and therefore affects gain determination.
      • Would like to use Mike's new hist-fit-adjust method with new geometry to get new set of gains.
      • Changes to code are currently on a branch. Sean: When to merge? Matt: does not have a strong preference except to determine new gains will all new inputs at the same time.
      • Timing: current algorithm takes the time of the largest energy block (sigma~0.3 ns). improved algorithm: uses energy weighted times of hit blocks (sigma~0.25 ns). Both estimate are energy dependent. Timing in MC is a constant sigma~0.4 ns.
      • Matt: Asked Mark about study to investigate eta resolution in Fcal. In particular, what is the constant term? (FCAL data seems to indicate a high 6-7 % constant term). Mark: Will report back on results of eta study in FCAL.
5. BCAL update
6. Calibrations
7. Reconstruction and Simulation
   1. 2017 mcsmear Workplan
8. NIM articles
   1. Bcal
      • Elton posted the latest draft of the BCAL NIM paper on the portal ([https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=3385 GlueX-doc-3385)
      • MC analysis of pi0 data (Will) yields a very small constant term (~1%), and eta data (Mark) yields a constant term of about 4%. The MC has been updated with a constant term of about 3.7. What is the discrepancy?
      • Will confirmed that he is using the latest MC with the large constant term.
      • Mark: It could be that the 3.7% constant term for individual cells averages out to a smaller value. This should be investigated.
      • Mark: The pi0 plot is one of the difference between generated-true values, while the eta data is extracted from measurements. This plot can also be made for eta MC for comparison.
9. Any other business