Difference between revisions of "JEF meeting, August 27, 2021"
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::- [https://logbooks.jlab.org/entry/3897600 Adjusting LED system for CCAL] -- Sasha | ::- [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 2π0 and 2η 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 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? |
Latest revision as of 11:02, 30 August 2021
Meeting time and location= 9:30 am EST (JLab time) Bluejeans only
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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
- Observed considerable peaking background from η→2γ, probably arising from conversions/split-offs
- 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
- Offline discussion summary:
- 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
- Ran simulations for both GlueX and JEF conditions
- 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?