Difference between revisions of "JEF meeting, August 13, 2021"
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** [https://halldweb.jlab.org/wiki-private/index.php/File:JEF_8.10.21.pdf Using MC Trajectories in simulations] (Jon) | ** [https://halldweb.jlab.org/wiki-private/index.php/File:JEF_8.10.21.pdf Using MC Trajectories in simulations] (Jon) | ||
* Meeting time | * Meeting time | ||
+ | |||
+ | =Minutes= | ||
+ | Attendees: Varun,Igal,Joanna,Zisis,Arshak,Chase,Liping,Sasha,Azizah,Bill B.,Tim B.,Jane,Jon,Phil,Olga,Susan,Jane,S.T. | ||
+ | * No update from SICCAS regarding test samples for production of new crystals | ||
+ | * Procedure for wrapping crystals has been updated (presented by Joanna(UNCW)): [https://halldweb.jlab.org/detectors/fcal2/module_fabrication/Crystal_Wrapping_Procedure.docx] | ||
+ | * Crytur confirmed can produce crystals (want to be fully loaded) | ||
+ | * COMCAL has been installed in the hall | ||
+ | ** Light monitoring system: all channels checked, some channels were unstable (drifting amplitudes, due to poor connections on PMT socket?) | ||
+ | *** Two channels replaced, some optical fibers reglued | ||
+ | ** Found problem with one of 5 thermal sensors, will operate with 4 | ||
+ | ** About to move to platform for positioning on beam line | ||
+ | * Chase presented update on using TMVA for background suppression for η→π0γγ channel | ||
+ | ** Compared Boosted Decision Trees (BDT) to Fisher discriminants | ||
+ | ** 15 input variables: tested various combinations | ||
+ | ** BDT works better than Fisher | ||
+ | * Igal looked at applying BDT to simulations of signal (η→π0γγ) and background, and to 2017 data | ||
+ | ** Looking at γp→4γp | ||
+ | ** Vetoed 2π0, ηπ0 and 2η channels using 5σ cut | ||
+ | ** Required all photons in FCAL and a fiducial cut to avoid getting too close to beam hole | ||
+ | ** Monte Carlo: found large peaking background due to η→2γ | ||
+ | *** Not reported by previous experiments -- need to understand source | ||
+ | ** Using 4-vectors after kinematic fit sharpens features in mass distributions | ||
+ | ** Apply cut on BDT greatly reduces background below signal region | ||
+ | * Jon briefly showed the z-positions where conversions of photons occur as part of a presentation about using MCTrajectory information from the simulation |
Latest revision as of 16:10, 13 August 2021
Meeting time and location= 9:00 am EST (JLab time) Bluejeans only
Connection instructions
We are using BlueJeans Video/Audio conferencing. Our meeting ID number is 992533564. Click "Expand" for more details.
- Make sure you have created a BlueJeans account via your JLab CUE account using this link:
- http://jlab.bluejeans.com (You should only need to do this once)
- If connecting via Web Browser: click this link (no passcode is needed):
- If connecting via Phone: Dial one of the following numbers and then enter the meeting ID above and hit "#" or "##"
- Dial: 1 888 240 2560 (US or Canada only)
- or, List of International Numbers
- If connecting via Polycom unit:
- Dial 199.48.152.152 or bjn.vc
- Enter meeting ID above
Agenda
- SICCAS crystals
- Module fabrication
- COMCAL tests, TAC running, etc.
- Data analysis
- Simulations
- Meeting time
Minutes
Attendees: Varun,Igal,Joanna,Zisis,Arshak,Chase,Liping,Sasha,Azizah,Bill B.,Tim B.,Jane,Jon,Phil,Olga,Susan,Jane,S.T.
- No update from SICCAS regarding test samples for production of new crystals
- Procedure for wrapping crystals has been updated (presented by Joanna(UNCW)): [1]
- Crytur confirmed can produce crystals (want to be fully loaded)
- COMCAL has been installed in the hall
- Light monitoring system: all channels checked, some channels were unstable (drifting amplitudes, due to poor connections on PMT socket?)
- Two channels replaced, some optical fibers reglued
- Found problem with one of 5 thermal sensors, will operate with 4
- About to move to platform for positioning on beam line
- Light monitoring system: all channels checked, some channels were unstable (drifting amplitudes, due to poor connections on PMT socket?)
- Chase presented update on using TMVA for background suppression for η→π0γγ channel
- Compared Boosted Decision Trees (BDT) to Fisher discriminants
- 15 input variables: tested various combinations
- BDT works better than Fisher
- Igal looked at applying BDT to simulations of signal (η→π0γγ) and background, and to 2017 data
- Looking at γp→4γp
- Vetoed 2π0, ηπ0 and 2η channels using 5σ cut
- Required all photons in FCAL and a fiducial cut to avoid getting too close to beam hole
- Monte Carlo: found large peaking background due to η→2γ
- Not reported by previous experiments -- need to understand source
- Using 4-vectors after kinematic fit sharpens features in mass distributions
- Apply cut on BDT greatly reduces background below signal region
- Jon briefly showed the z-positions where conversions of photons occur as part of a presentation about using MCTrajectory information from the simulation