sPHENIX HCal discussion

[Stefan Bathe <bathe AT bnl.gov>]

Dear All,

Here some notes from today’s meeting (presenters, please post slides to indico!):

- Ejiro (slides)—update on Geant simulation
 - showed tower-by-tower energy distributions (goal:  eta dependence)
 - suggestions:
   - correct tower energy for path length (angular dependence)
   - plot tower energy mu and sigma vs eta
   - MC distribution can be used as fit sample for experimental data
   - sample plane over entire sector and sample angular distribution to mimic experimental data

- Dan Lis (verbal)—working on:
 - full sector (i.e. with half-absorber plates for top and bottom) rather than segment of full detector as proxy
 - cosmic spray class different from particle gun
 - event display

- Hanpu (slides)—fitting update
 - showed update on results of combination of peak finder (to fix range for fit) and gamma distribution fit (to extract mean)
 - work reliably now so it can be used for both calibration and tower QA (2 % statistical uncertainty; fit looks good so that systematic uncertainty probably low)
 - fit uncertainty similar to systematic difference between fit and peak finder peak location
 - suggestions:
   - exclude non-suitable data (e.g low statistics, rotation test, wrong voltage)
   - correct for tile Performance Ratio (PR):  see info below
   - quantify chi^2/ndf

Shuhang (slides)—fitting update
- broke down long run into subsamples
 - no significant differences
 - peak finder shows systematic shift depending on statistics (since bin width depends on statistics)
 - shift goes up as statistics go down; gamma distribution fit still above peak finder (see Hapu’s slides); points to some systematic error in gamma distribution fit
 - but fit probably (awaiting chi^2/ndf, see above) good enough
 - first of three recent burn-in runs for sector 13 shows vastly lower ADC mean:  concern
 - need run list with comments, problems, and solutions on wiki
 - have elog:  https://sphenix-intra.sdcc.bnl.gov/WWW/elog/HCAL/ 

Veronica (verbal update)—fitting update
- looking into recent burn-in runs with corrected voltage for production SiPMs
 - MPV changed
 - but no analysis yet

Dan Lis (slides)
- plotted ADC peak vs integral
- linear for some channel, non-linear (plus fluctuations) for others
- concern
 - suggestion:  does pattern repeat for different runs?


Links:
Calibration wiki location:
https://wiki.bnl.gov/sPHENIX/index.php/HCal_Calibration
Tile Installation db:
https://docs.google.com/spreadsheets/d/1rIUAVjWNd7wE9ms2BfCqUAGH0KbNNxG7OtwXJJKNzWY/edit?usp=sharing  
elog location:
https://sphenix-intra.sdcc.bnl.gov/WWW/elog/HCAL/

Regards,
Stefan
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Stefan Bathe
Professor of Physics
Baruch College, CUNY

Baruch:                                     BNL:
17 Lexington Ave                      Bldg. 510
office 940                                  office 2-229
phone 646-660-6272                phone 631-344-8490
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On May 31, 2021, at 10:27 PM, Stefan Bathe <stefan.bathe AT baruch.cuny.edu> wrote:

Dear All,

We’ll have our next HCal muon calibration meeting tomorrow, Tuesday, June 1, at 11:00am.

Here’s a link to the agenda:

https://indico.bnl.gov/event/12037/

The zoom info is on the agenda page and also at the bottom of this message.

(We had a brief get-together also at the end of last week’s HCal meeting.  I created an indico agenda page for that meeting after the fact here:  https://indico.bnl.gov/event/12036/  If those who presented could please upload their talks there, that would be great.)

Regards,
Stefan

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Stefan Bathe is inviting you to a scheduled Zoom meeting.

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---------------------------------------------------------------------------------
Stefan Bathe
Professor of Physics
Baruch College, CUNY

Baruch:                                     BNL:
17 Lexington Ave                      Bldg. 510
office 940                                  office 2-229
phone 646-660-6272                phone 631-344-8490
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