Difference between revisions of "JEF meeting, August 27, 2021"

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(Created page with "Meeting time and location= 9:30 am EST (JLab time) Bluejeans only =Connection instructions= <div class="toccolours mw-collapsible mw-collapsed"> We are using [https://cc.jla...")
 
(Minutes)
 
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* Module fabrication
 
* Module fabrication
 
* COMCAL tests, TAC running, etc.
 
* COMCAL tests, TAC running, etc.
 +
::- [https://logbooks.jlab.org/entry/3897600 Adjusting LED system for CCAL] -- Sasha
 
* Data analysis
 
* Data analysis
 +
::- [https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=5245 2&pi;0 and 2&eta; studies] -- Annika Thiel
 +
::- [https://halldweb.jlab.org/DocDB/0052/005239/003/glue-jefxd-igal-jaegle-27082021.pdf \eta \to \gamma\gamma\pi^0]
 
* Simulations
 
* Simulations
 +
 +
=Minutes=
 +
Attendees: Bill B., Olga, Phil, Zisis, Arshak, Jon, Susan, Azizah, Igal, Annika, Liping, Sasha, Jane, S.T.
 +
* SICCAS received shipment of new raw material, producing test crystals now; plan to wait ~2 weeks for results
 +
** Powder from previous vendor --> poor quality crystals
 +
** Delivery schedule is still unknown
 +
* COMCAL has been installed on platform and re-surveyed
 +
** Still tilted but not as badly as before
 +
** Sasha checked out COMCAL response using LED and alpha source
 +
*** LED response using amplitudes wider distribution than expected (hoped for?)--> spread in light distribution
 +
** Adjusted HV, checked timing --> things are starting to look good
 +
*Light uniformity from LMS is a concern for FCAL-II; plan to use different LED colors just like done for FCAL
 +
* Fernando has prototype for PMT divider for NPS, working on tuning design for them, then for us
 +
** Hope to test during upcoming runs, can even be during CPP next year, but want to set a deadline for the middle of next year
 +
* Igal gave an update on his &eta;&rarr;&pi;0&gamma;&gamma; analysis
 +
** Ran simulations for both GlueX and JEF conditions
 +
*** Observed considerable peaking background from &eta;&rarr;2&gamma;, probably arising from conversions/split-offs
 +
**** Looked at ways to reduce or eliminate this contamination
 +
** Found expected number of &pi;0&gamma;&gamma; events to be roughly consistent with the JEF proposal
 +
** Found the amount of beam time needed for production of 50M &eta;s with recoil proton required to be roughly an order of magnitude longer than the proposal estimate
 +
*** Offline discussion summary:
 +
**** Clarify the meaning of 50M tagged eta i.e. eta with a detectable recoil proton (eta can possibly not pass the selection criteria)
 +
**** Out of 50M tagged eta, 1/4 is expected to pass the selection criteria
 +
**** Expected integrated luminosity for phase IV is 315 pb-1 ie for 100 PAC days, ~ 1fb-1 should be collected
 +
**** After re-compiling all numbers, the signal observed is consistent with simulation expectation
 +
** Found that the kinematic fit is distorting the mass distributions (sometimes moving peaks away from the physical mass values)
 +
** TMVA results briefly touched on, but signal after applying cut on BDT response seems high possibly due to a bug in DSelector that is treating g1g2 and g2g1 as two different combination
 +
* Annika presented some results of her &gamma;p&rarr;p2&pi;0,p2&eta; analysis
 +
** Background in 2&eta; channel is high, but reduced by imposing a &pi;0 veto
 +
** Handled background by looking at side-band regions in 2D
 +
** See considerable 2&pi;0 strength at low mass consistent with f0(500)
 +
** We had a discussion regarding simulation of these events
 +
*** Annika currently using genr8, looked into using amptools without much success
 +
*** Use mass distributions from data?

Latest revision as of 10:02, 30 August 2021

Meeting time and location= 9:30 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

  • SICCAS crystals
  • Module fabrication
  • COMCAL tests, TAC running, etc.
- Adjusting LED system for CCAL -- Sasha
  • Data analysis
- 2π0 and 2η studies -- Annika Thiel
- \eta \to \gamma\gamma\pi^0
  • Simulations

Minutes

Attendees: Bill B., Olga, Phil, Zisis, Arshak, Jon, Susan, Azizah, Igal, Annika, Liping, Sasha, Jane, S.T.

  • SICCAS received shipment of new raw material, producing test crystals now; plan to wait ~2 weeks for results
    • Powder from previous vendor --> poor quality crystals
    • Delivery schedule is still unknown
  • COMCAL has been installed on platform and re-surveyed
    • Still tilted but not as badly as before
    • Sasha checked out COMCAL response using LED and alpha source
      • LED response using amplitudes wider distribution than expected (hoped for?)--> spread in light distribution
    • Adjusted HV, checked timing --> things are starting to look good
  • Light uniformity from LMS is a concern for FCAL-II; plan to use different LED colors just like done for FCAL
  • Fernando has prototype for PMT divider for NPS, working on tuning design for them, then for us
    • Hope to test during upcoming runs, can even be during CPP next year, but want to set a deadline for the middle of next year
  • Igal gave an update on his η→π0γγ analysis
    • Ran simulations for both GlueX and JEF conditions
      • Observed considerable peaking background from η→2γ, probably arising from conversions/split-offs
        • Looked at ways to reduce or eliminate this contamination
    • Found expected number of π0γγ events to be roughly consistent with the JEF proposal
    • Found the amount of beam time needed for production of 50M ηs with recoil proton required to be roughly an order of magnitude longer than the proposal estimate
      • Offline discussion summary:
        • Clarify the meaning of 50M tagged eta i.e. eta with a detectable recoil proton (eta can possibly not pass the selection criteria)
        • Out of 50M tagged eta, 1/4 is expected to pass the selection criteria
        • Expected integrated luminosity for phase IV is 315 pb-1 ie for 100 PAC days, ~ 1fb-1 should be collected
        • After re-compiling all numbers, the signal observed is consistent with simulation expectation
    • Found that the kinematic fit is distorting the mass distributions (sometimes moving peaks away from the physical mass values)
    • TMVA results briefly touched on, but signal after applying cut on BDT response seems high possibly due to a bug in DSelector that is treating g1g2 and g2g1 as two different combination
  • Annika presented some results of her γp→p2π0,p2η analysis
    • Background in 2η channel is high, but reduced by imposing a π0 veto
    • Handled background by looking at side-band regions in 2D
    • See considerable 2π0 strength at low mass consistent with f0(500)
    • We had a discussion regarding simulation of these events
      • Annika currently using genr8, looked into using amptools without much success
      • Use mass distributions from data?