Difference between revisions of "JEF meeting, August 13, 2021"

From GlueXWiki
Jump to: navigation, search
Line 30: Line 30:
 
** [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→4γ
 +
** 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

Revision as of 16:09, 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:
  • 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 "##"
  • If connecting via Polycom unit:
    • Dial 199.48.152.152 or bjn.vc
    • Enter meeting ID above

Agenda

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
  • 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→4γ
    • 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