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Kaon LT Meetings » mtg_23aug17.txt

Garth Huber, 08/17/2023 06:23 PM

 
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                 Aug 17/23 PionLT/KaonLT Analysis Meeting Notes
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                 ----------------------------------------------
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                                (Notes by GH)
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                     Today: PionLT will be discussed first
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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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-------
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Regina - Garth Huber, Nathan Heinrich, Nacer Hamdi, Alicia Postuma,
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   Muhammad Junaid, Vijay Kumar
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JLab - Dave Gaskell
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CUA - Richard Trotta
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CSULA - Konrad Aniol
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Nathan Updates
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--------------
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HGCer Calib Update
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- parameter equation in standard.database
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- changes pushed to GitHub
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- comparison w/ online HGC plots
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   - NPE distribution goes much higher now, particularly for last runs of
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     experiment, where gain drop was significant
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- will post slides on calib after final set of runs is completed on ifarm
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Working on standard.kinematics
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Junaid Updates
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--------------
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HMS Calorimeter Calib
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- working on 9.177 GeV (2021) data
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- marged Nathan's changes
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- calibrating once a shift now
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  - DG: question on whether it is needed to calibrate this frequently
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  - MJ: sees shifts after 2-3 days, so need fairly often
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GH: please have a discussion with Nathan, and come up with a plan on how many
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runs need to be calibrated, and how long do you expect it to take
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- concerned that MJ will feel stuck working on calibrations for a very long
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  time, so we should see if we can finish by Labor Day, if possible
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Richard Updates
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---------------
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Changes to mc_shms_hut.f for calorimeter edge cut
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- it was commented out in RT's version, but NOT commented out in SIMC master
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- DG: these cuts can be done either in a standalone script, or in SIMC, it's a
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  matter of what you prefer
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Aerogel tray cuts now implemented in recon_hcana script
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Implementing HGC hole cut
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- will discuss this more w/ Ali after he's back
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Kinematics averaging code is now simpler, replicating old Fortran code
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- now just taking average kinematics per t-bin
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Will give an update on Lumi scans status next week
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Vijay Updates
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-------------
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Confirmed that calorimeter edge cut is NOT commented out in his SIMC
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Target boiling corrections work in progress
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- hoping to show some plots next week
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Alicia Updates
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--------------
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Follow up from Portia's work on piDelta BSA
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- Portia did not have weighted SIMC plots, adding weights improved things a lot
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- also a small error in phi conversion between Data & SIMC corrected
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- No Dummy subtractions yet (but Randoms are subtracted)
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- Using SIDIS & piDelta MC output for MM-distribution shape
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- fit to data looks very good (Q2=2.115)
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- pi+n radiative tail also not yet included
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  - plot including radiative tail shows a significant contribution underneath
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    piDelta peak
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- Preliminary BSA plot (Center only)
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  - integrated fitted piDelta MC to data
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    - expecting a large systematic uncertainty from the fit
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  - only one t-bin so far, possibly the Q2=2.115 can have two t-bins
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  - DG: HERMES had only one t-bin, but they removed the -t_min region (where
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    asymmetry is small) so that the remaining region had a larger BSA
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pi+n Binning
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- Q2=5.5: decided to have 4 t-bins rather than 5
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  - trying different phi-bin options: 9, 11, 13 bins
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  - DG: should get same asymmetry for all choices of phi-bins, provided there
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    are sufficient bins to fit the asymmetry moments
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    - in general, more bins are better
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  - 13 phi-bins looks good for Q2=5.5
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  - GH: please make a table of fitting results & errors vs #phi bins, so we can
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    check fit stability and trends
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  - DG: a little worried about the dependence on #phi bins, suggests a MC study
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    to see if there are any issues, such as e.g. if 9 phi-bins are sufficient
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  - Q2=4.4: 5 t-bins seems fine
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    - results with both 13, 15 phi-bins look okay
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    - 13 bins has a bit more wiggles
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  - Q2=3, W=2.32: 7 t-bins
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  - Q2=3, W=3.14: 7 t-bins
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    - this set has very good statistics
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  - Q2=2.115: 8 t-bins
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    - first t-bin has nearly zero asymmetry, very close to -t_min
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      - fit with A,B,C a bit weird, looks reminiscent of a capacitor breakdown
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        plot
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      - NG: there should be a way to tell ROOT the bins have a width, that
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        might get rid of the weird fits
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      - Nacer: has a small function that AP can try
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BSA Error Analysis
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- tried to re-derive error equation in S.Diehl's paper
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  - Diehl's eqn seems to be based on the approximation
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    Y+ \sim Y- which leads to Y+^2 + Y-^2 \sim 2Y+Y-
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    - DG confirms this is a common choice in PV experiments
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  - Alicia's formula has no approximations, is exact
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    - approximate formula leads to an under-estimation of errors
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    - difference between exact formula and approximate formula is small in most
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      cases, but the deviation grows for points where the BSA > 0.1
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      - Diehl BSA < 0.1, so difference not significant for those data
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    - we will use Alicia's formula, since it is more accurate
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Next Meeting
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------------
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- Thur Aug 24 @ 16:00 Eastern/14:00 Regina/13:00 Pacific
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- KaonLT will go first
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