View source for May 3, 2018 Calorimeter

=Video Conferencing Information=

''<font color=red>Meeting Time: 11:00 a.m.</font>''

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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 =
# Homework from NIM paper.  Non-linearity correction of SiPMs (Elton)
# Enrich pi0 skim with layer 3 events (Tegan with support from Sean/Mark)

Complete after new launch
# Report back on study of eta with in FCAL [Mark]
# From Mike's work: -cos(phi) type dependence in the data and a phi dependence at the downstream end of the bcal

= References =

# FCAL [https://logbooks.jlab.org/book/hdfcal HDFCAL log book]
# BCAL [https://logbooks.jlab.org/book/hdbcal HDBCAL log book]

= Tentative Agenda =
 
# Announcements
# Action Items
# Run Updates
## FCAL
##* [https://logbooks.jlab.org/entry/3570357 Log Entry 3570357] (Colin)
##* Turn off LED pulser?
## BCAL
##* One bad TDC channel to be investigated
##* Turn off LED pulser
# Calibrations
#* [[Calibration_Dashboard#Spring_2018_Calibrations | Calibration Dashboard]]
# Monitoring
# Reconstruction and Simulation
## From Carlos Salgado:
##* Simulating gp->eta pi0 p -> 4 gammas p. Cutting on Chi2 of fit generates a hole at phi=0 in the GJ frame. This appears to be due to poor (fit) reconstruction of photons in the FCAL generating poor Chi2. 
##* Carlos will collect plots showing the problem, but this should be investigated. 
## BCAL clustering update on far away points [https://logbooks.jlab.org/entry/3571066] (Will M.)
# NIM articles
# Any other business

= Minutes =
''Attending: Elton, Mark (JLab); Matt (IU); Wil, Curtis (CMU); Zisis, Tegan, Ahmed (UofR); Sean (FSU); Christina, George (Athens); Tolga (FIU).

# Announcements
#* Alexandre came in first in the run-around.
#* 12 GeV Project celebration this week featured DOE officials and government representatives
# Action Items
#* No updates
# Run Updates
## Accelerator has been down since yesterday with network issues. Physics run is ending at 5 am Sunday.
##* Shutdown lists are being prepared. Electronic racks will be left on.
## FCAL
##* [https://logbooks.jlab.org/entry/3570357 Log Entry 3570357] (Colin)
##* Keep HV on for a couple of weeks to monitor base failures
##* Turn off LED pulser? Mark: Keep on as long as HV is on for checks of bases.
## BCAL
##* One bad TDC channel to be investigated this summer
##* Turn off LV and bias and LED pulser. Turn chiller up to 18 deg for the summer.
# Calibrations
## [[Calibration_Dashboard#Spring_2018_Calibrations | Calibration Dashboard]]
## BCAL gains (Tegan)
##* Current constants have not been added to ccdb. Latest iteration saw a change in pi0 mean, but farm access has been slow and now further iterations have been completed. Constants will be entered into ccdb and updated later with better constants if needed.
##* Sean: Tegan will send list of skimmed files to disk so that they can be pinned during calibrations.
##* Elton: Have you tried the non-linear calibrations? Not yet. Tegan will contact Will for information about the procedure.
##* Sean: Request that Tegan update him weekly on calibration status.
# Monitoring
# Reconstruction and Simulation
## From Carlos Salgado:
##* Simulating gp->eta pi0 p -> 4 gammas p. Cutting on Chi2 of fit generates a hole at phi=0 in the GJ frame. This appears to be due to poor (fit) reconstruction of photons in the FCAL generating poor Chi2. 
##* Carlos will collect plots showing the problem, but this should be investigated. 
##* Mark: Need to work on MC as we do on data for both BCAL and FCAL
##* Matt: Features in MC not modeled correctly. Last fall corrections were used to set the overall scale in the MC.
##* Sean: Single photons were used to make the on-linear correction. Residual problems remained at low energies that could not be accommodated with the functional form used for data.
##* Matt: Suggests that Carlos check raw data distributions (e.g. pi0 and eta masses) and verify stability with kinematics
##* Curtis: Is the MC up-to-date? Elton: Carlos has been working with Thomas, so the MC is probably recent.
##* Will: Used single photon MC last year to make the non-linear corrections in MC. Checked that this yielded consistent results with pi0 determinations
## BCAL clustering update on far away points [https://logbooks.jlab.org/entry/3571066] (Will M.)
##* Investigating the discrepancies found for J/Psi events identified by Lubomir and Sean. These generated unphysical z and time values for some clusters
##* Revisiting changes to the charged particle clusterizer.
##* New procedures seem to fix the observed problems.
##* Almost ready to check in the new code. However, an issue was observed related to the last point not being included in a cluster. Need to add extra merging criteria for fix. 
##* Mark: Are these issues due to charged particle clusterizer only? Yes, the neutral clusters exclude these points do do not have biased position and times but do loose the energy.
##* Sean: These problems may be due to shadowing of real hits by noise.
##* Matt: May be useful to explore these issues using full waveforms in raw data that is collected regularly.
##* Almost ready to check in changes.
# NIM articles
#* Reference to BCAL NIM have been added to the arXiv and JLab publication db.
# Any other business
#* Tegan and Ahmed are traveling to JLab next week and will be here May 10-19 and attend the software workshop.