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Kaon LT Meetings » mtg_22sep08.txt

Garth Huber, 09/08/2022 05:55 PM

 
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                Sept 8/22 PionLT/KaonLT Analysis Meeting Notes
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                ----------------------------------------------
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                           (Notes by GH and SJDK)
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Please remember to post your slides at:
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https://redmine.jlab.org/projects/kltexp/wiki/Kaon_LT_Meetings
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Present:
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Regina - Stephen Kay, Garth Huber, Vijay Kumar, Muhammad Junaid,
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   Alicia Postuma, Jacob Murphy, Ali Usman, Love Preet
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CUA - Richard Trotta, Tanja Horn
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Ohio - Jacob Murphy
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CSULA - Konrad Aniol
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Richard Updates
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---------------
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- Lumi 10.6GeV Analysis
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   - PID cuts updated
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   - Scaler, Without, and with tracking cuts
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   - Statistical uncertainties now too (but not yet including statistical from
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     efficiencies)
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   - Normalized yield results vs. Current for HMS-Carbon
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      - Blue: total LT, red: CPULT
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      - Scaler vs Event (no tracking) vs Event (tracking)
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      - Large discrepancy between the two, with the CPULT results being MUCH
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        better
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   - SHMS-Carbon analysis shows "reverse boiling" of 14% @ 70uA
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      - SHMS sees a trend even with poor TLT runs removed
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   - Some Lumi runs are not great
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      - <90 seconds of "good" beam on time after current cuts
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      - Bi-modal distribution of current within some runs
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      - GH note afterward: Yes, the 10.6GeV beam current was extremely
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        unstable.  The 8,6GeV lumi scans should be much better!
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   - some CPULT as low as 75%, possible due to excessive EDTM rates for some
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     low current settings.  EDTM should have smaller effect in high current
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     runs, where PS is set high
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      - Jacob asks about CPULT eqn used.  Does it include Carlos' Poisson
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        correction discussed in his thesis?
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      - It sounds like the answer is No, but Richard should double-check
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   - See large inverse boiling trend with scalers in some scans which goes away
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     in untracked and tracked analysis
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      - Bad scaler yields correspond with CPULT drops
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      - This is *very* worrisome, as the scaler analysis should be insensitive
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        to deadtime effects.  *Definitely* needs more investigation!
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- Next up:
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   - Offsets
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   - Lumi analysis, cut iterations
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   - HeeP/Lumi uncertainties
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   - Bill's code
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   - HeeP Singels efficiencies issues
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   - Calorimeter Calibrations
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   - HGC efficiency calculation
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- Vijay: TLT vs CPULT, which should be used?
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   - Dave G recommended CPULT previously
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      - Generally fairly consistent between the two
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   - Garth: EDTM system between KaonLT/PionLT, major difference between the two
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     experiments.  This will be one of the causes of larger systematic error in
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     KaonLT compared to PionLT
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      - EDTM system updates were only ready for 2021 run, low Q2 PionLT (summer
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        2019) still had the old verion?
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      - As a result, the uncertainty in TLT might be too big to use in some
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        parts of KaonLT, and we would have to use CPULT with a correction to
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        account for Electronic DT
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- FADC reference timing and CoinTime changes were done during the early parts
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  of KaonLT, as deficiencies in the SHMS+HMS commissioning setup were identified
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   - CoinTIme change was after the 10.6 GeV, but before the 3.9 GeV and 4.8 GeV
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      - CT changes
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      - Leading edge vs falling edge
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      - Inverted signal
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      - DaveG indicates (afterward) that this was error introduced summer 2018,
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        were ALL reference time signals were inverted.  The main effect of this
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        was crappy CoinTime resolution, as its more sensitive to jitter in
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        signal timing
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   - Hodoscope timing changes
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      - Mark changed how the different hodoscope planes define the FADC reference time 
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         - intial timing had each plane with a different time, with S1X last,
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           leading to multiple peaks
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         - later, after more understanding, the timing was changed so that most
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           events are in a single peak
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	 - DaveG thinks this occurred before J/Psi run in early 2019
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      - All S1X were were synchronized by Simona at some point, to reduce
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        timing jitter between different paddles
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	 - this allowed the S1X, S1Y timing windows to be narrowed, which then
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           helped reduce Electronic DeadTime (significant impact in some cases)
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         - DaveG thinks this was done in summer 2018, before KaonLT
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   - Someone should identify exactly when these confiugration changes occured
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      - Ali will check, it would be helpful for Vijay to assist, since neither
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        were present at the beginning of KaonLT data taking
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      - Stephen skimmed the logbooks, some potential entries to look at (to begin with)
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         - https://logbooks.jlab.org/entry/3629548
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         - https://logbooks.jlab.org/entry/3630734
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         - https://logbooks.jlab.org/entry/3630346
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         - https://logbooks.jlab.org/entry/3614446
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         - https://logbooks.jlab.org/entry/3614481
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         - https://logbooks.jlab.org/entry/3626160
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         - https://logbooks.jlab.org/entry/3626194
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   - Could add issues to wiki once found?
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      - There are status pages for KaonLT, Summer 2019 PionLT
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      - Add information to this
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Ali Updates
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-----------
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- High Q2 HeePCoin analysis
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   - Ali/Richard looking at 6.2/8.2/10.6 GeV HeePCoin settings
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   - Summarizes the Emiss/Pmiss distribution issues discussed last week
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   - Debug Test #5
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      - Stephen redid tests 1-4, discovered that files in high Q2 comparison
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        test were different, confirmed that the problem is in hcana, not python
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	script analysis
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      - problem was a wrong gbeam.param file, which was for polarized 3He
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        target data taking, where there is a large solenoidal field at the target
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      - now have much narrower EM/PM peaks, which will allow the offsets to
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        finally be determined from these data
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   - Need consistent set of offsets
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      - Momentum offset changes if the magnets saturate
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      - Magnet settings for each beam energy
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         - 10p6: p_h = -6.590, p_p = +4.484
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         - 8p2: p_h = -4.672, p_p = +4.371
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         - 6p2: p_h = -3.571, p_p = +3.486
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         - 4p9: p_h = -3.124, p_p = +2.583
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         - 3p8: p_h = -2.026, p_p = +2.583
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- What is the correct gbeam.param file?
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   - issue is that there are multiple versions of some variables in Vijay's
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     version of the 2018 file
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      - need to confirm that used file for KaonLT is correct
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   - Dave G seemed to imply (offline) that this is the one should use:
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      - https://github.com/JeffersonLab/hallc_replay_lt/blob/LTSep_Analysis_2022/PARAM/GEN/KaonLT_PARAM/gbeam_fall18.param
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      - Implied we should use a different file altogether for Summer2019
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      - possibly we need to generate a new one for PionLT 2021-22, from harp scan data
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   - Emiss vs delta(HMS,SHMS) plots have a tilt (8.2 GeV setting)
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      - Happened for all settings except 10.6 GeV
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      - Should also add plot of HMS vs SHMS delta   
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   - Tanja mentions we saw the effect of raster offset causing a MM vs delta
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     correlation in Fpi2
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      - error in raster correction causes an offset in vertical angle at target
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      - strong correlation of angle vs momentum in Heep-Coin makes the effect
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        visible in Heep MM vs delta
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      - the error would be present also in the pi/K data, but the effect would
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        be mostly in worse MM reconstruction resolution, not seen as a clear
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       correlation, as this would be disguised by the 3-body (rather than
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       2-body) kinematics
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- How do we apply correct raster offsets?
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   - In gbeam.param, beam on target positions are commented out?
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   - Do these actually adjust anything? Should we set them to our nominal values?
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   - Check and follow up with Dave G
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- Efficiencies file
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   - Run by run efficiency, propagated error should be statistical
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     uncertainties that are added in quadrature to statistical uncertainty of data
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Vijay Updates
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- Working on Lumi studies, no updates
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Junaid/Nathan Updates
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- No updates, comprehensive preparation
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Jacob Updates
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- No big updates
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- Lumi scripts + calibrations
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Stephen
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- Some discussion on topics to be discussed in October Hall C Analysis Meeting
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   - meeting is planned to be ~2 hours long
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   - 6 to 8 talks in total (GH thinks this might be too many)
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   - Richard Lumi scan and Livetimes
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   - Jacob EDTM and Prescale studies
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   - Ali/Vijay gbeam.param
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Next Meeting:
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- Wed Sept 21 at 06:00 Pacific/07:00 SK/09:00 Eastern
(80-80/413)