Difference between revisions of "April 20-21, 2020 DIRC"
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* Comparison of corrections | * Comparison of corrections | ||
** Need to keep track of both SPR improvement and difference between thetaC mean with improvements | ** Need to keep track of both SPR improvement and difference between thetaC mean with improvements | ||
| − | ** Kaon | + | ** Kaon DeltaLL narrows as corrections improve performance |
| + | * Kaon photon yield significantly higher than pion | ||
| + | ** Need to look back at MC for comparison of photon yield between pions and kaons | ||
| + | ** Should cut on thetaC for counting photons be symmetric around pion and kaon peaks separately? | ||
| + | * Event selection for calibration sample: | ||
| + | ** Look at side-band of phi mass distribution in thetaC plot | ||
| + | ** Cleaner sample: Use comparison of 2pi and 2k | ||
| + | ** For some reason don't see peak for opposite particle type, e.g. kaons peaking at DeltaLL. | ||
| + | *** Select poorer kaon sample (e.g. with inverted chi2 cut) | ||
| + | *** Study event selection plots: mass distribution (phi/rho yield), kinfit chi2, etc. after positively identifying a kaon | ||
| + | |||
| + | === General === | ||
| + | * Data/MC comparisons | ||
Revision as of 10:07, 20 April 2020
Contents
Meeting Information
GlueX DIRC Meeting
Monday-Tuesday April 20-21, 2020
Remote only
Connection Using Bluejeans
- To join via Polycom room system go to the IP Address: 199.48.152.152 (bjn.vc) and enter the meeting ID: 846453895.
- To join via a Web Browser, go to the page [1] https://bluejeans.com/846453895 .
- To join via phone, use one of the following numbers and the Conference ID: 846453895
- US or Canada: +1 408 740 7256 or
- US or Canada: +1 888 240 2560
- More information on connecting to bluejeans is available.
Agenda
Monday, April 20
- 9:00 - Status of geometric reconstruction --- Roman
- 9:45 - Status of Cherenkov PDF reconstruction --- Ahmed
- 10:30 - Break
- 11:00 - Status of DIRC-external issues --- Justin
- 11:45 - Summary of run-dependent performance --- Bill
- Afternoon - Followup discussion and presentations
Tuesday, April 21
- 9:00 - FastDIRC status --- Yunjie
- 9:45 - Followup discussion and planning future work --- All
- 11:15 - GlueX bi-weekly meeting
Discussion notes
Roman
- Slide 2: Kaon distributions have more background SPR plot and likelihood distribution is wider for kaon than pions. Could the timing performance still be worse for kaons than pions
- Slide 3: Preferred correction order is always to begin with per-PMT Cherenkov angle correction, since it keeps ring segments connected. Smearing by either track resolution (ring fit) or chromatic correction
- Per-PMT Cherenkov angle correction
- Some PMTs with bad correction, could be checked with MC?
- Ring-fit correction
- Sensitive to start values for the fits: use average of pion and kaon expected values.
- How do the the correction factors vary over the DIRC plane?
- Can we determine a map of expected track corrections as a function of r, phi?
- Chromatic correction
- Possible to use MC with varying timing resolutions to see if it follows the expectation. From this we could determine what time resolution would be required to make significant chromatic correction
- Suggestion to divide time difference by path length to improve performance (from SLAC experience)
- Comparison of corrections
- Need to keep track of both SPR improvement and difference between thetaC mean with improvements
- Kaon DeltaLL narrows as corrections improve performance
- Kaon photon yield significantly higher than pion
- Need to look back at MC for comparison of photon yield between pions and kaons
- Should cut on thetaC for counting photons be symmetric around pion and kaon peaks separately?
- Event selection for calibration sample:
- Look at side-band of phi mass distribution in thetaC plot
- Cleaner sample: Use comparison of 2pi and 2k
- For some reason don't see peak for opposite particle type, e.g. kaons peaking at DeltaLL.
- Select poorer kaon sample (e.g. with inverted chi2 cut)
- Study event selection plots: mass distribution (phi/rho yield), kinfit chi2, etc. after positively identifying a kaon
General
- Data/MC comparisons
