June 11-12/26 PionLT/KaonLT Analysis Meeting Notes -------------------------------------------------- (Notes by GH) This week: KaonLT will go first Please remember to post your slides at: https://redmine.jlab.org/projects/kltexp/wiki/Kaon_LT_Meetings Thursday: Present ----------------- Regina - Garth Huber, Alicia Postuma, Nathan Heinrich, Muhammad Junaid, Dex Yadlowski, Nermin Sadoun JLab - Dave Gaskell Virginia - Richard Trotta CUA - Tanja Horn, Chi Kin Tam Alicia ------ - presented draft u-channel slides for next Wednesday's Hall A/C talk - plan to have preliminary LT-sep plots for the presentation fell through - Dave will send links to other Hall C VCS experiments - Hall C 12 GeV VCS result: https://www.nature.com/articles/s41586-022-05248-1 - it is backward angle, but doesn't go all the way to 180 degrees in the center of mass. It seems to focus on the area around ~140 deg - the recent run this year was for the VCS-2 experiment. The proposal for that is at: https://misportal.jlab.org/mis/physics/experiments/viewProposal.cfm?paperId=1102 - it has similar theta-cm coverage. Chi Kin ------- New KaonLT Q2=3.0 W=2.32 Results - Data/MC yield ratios ~0.9-1.25, based on empirical (linear or quadratic) fit of background in Lambda region - fits background left and right of Lambda peak - area underneath Lambda peak is not subtracted - *NB* Garth/Tanja: need to interpolate the background underneath the Lambda from left and right regions and subtract it too - plots of Data vs MC for kinematic variables look pretty good - sig_uns: sig_loeps very close to sig_hieps - L/T results: sigT ~228, sigL ~15, very different than Richard's results which had significant sigL - not unreasonable to assume that high sigL in Richard's results was due to pi+ background leaking into K+ yield - yields also differ from Richard's by 2x, this needs more investigation Richard ------- KaonLT - looking more carefully at background subtraction - investigating Garth's suggestion about using the piDelta region to scale the pion background subtraction in cases where pi+n region is too poorly populated to be reliable - considering an event-by-event weight to scale background, based on both pi+n and piDelta regions - will run SIMC for pi+Delta0 generation shortly - Garth suggests contacting Ali for his SIMC files, since he already ran this generator for his studies Junaid ------ - back now from Pakistan - working on slides for JLUO and CAP Congress presentations Nathan ------ PionLT Q2=5.0 setting - found an error in SIMC input file, P_shms was too wrong by 2 GeV/c, which could explain anomalous SIMC results for that setting PionLT Q2=6.0 W=3.19 setting - yields for Left-Center-Right SHMS at same epsilon still don't make sense - Left yield is ~10x Center - High epsilon Right yield is over-subtracted - compare to online analysis plots: - Center yield was ~2x Left yield - Low eps, Mid eps, High eps ratios all made sense - still investigating why he can't get similar results to online analysis - *NB* Garth suggests to compare charge per run between online and his analysis, to see if that narrows down where the problem might lie Friday: Present --------------- Regina - Garth Huber, Nathan Heinrich, Nacer Hamdi, Muhammad Junaid, Dex Yadlowski, Nermin Sadoun CUA - Chi Kin Tam Virginia - Richard Trotta Glasgow - Rachel Montgomery JMU - Gabriel Niculescu, Ioana Niculescu Nacer ----- KaonLT Q2=0.5 LT-sep - working on systematic uncertainty studies - finished Data yields w/ cut variation - still waiting on jobs for SIMC yields w/ cut variation - modifying scripts for syst study, additional plots, etc. - goal is to compute sig_uns for each cut variation Gabriel ------- MC Ratio applicability studies - Nathan sent a question by eail, to which they responded Nermin ------ PionLT LD2 Lumi studies Scaler yields - replayed 7.9 LD2 boiling study, scaler yield - combined HMS scaler scans for 6.4, 9.2-1, 9.2-2, 7.9 beam energies - obtain a combined slope of -3.37 +/- 0.35 %/100uA - *NB* to obtain the systematic uncertainty, Nathan took the standard deviation of the different scans, and subtracted the statistical uncertainties (in quadrature) to get the remaining systematic Tracked yields, 6.4 GeV beam energy, where EDTM should be reliable - black points = 6.4 tracked yields up to 80uA - blue points = 6.4 scaler yields, where the highest 80uA point was removed because the ELLT will be unreliable since rate was >200kHz - combined slope: -3.383 +/- 0.349 %/100uA, so consistent with scaler analysis Relative HMS Tracked yields - this study needs to use unstable CPULT calculated from equation - black points = 6.4 using TLT from EDTM - red,green = 9.2-1, 9.2-2 using ELLT*CPULT - the different sets are inconsistent @ 2.5% level, indicating there is probably an extra systematic on CPULT of ~2.5% Relative SHMS yields - needed to keep all runs below 600kHz, if applied same 200kHz criterion as for HMS, there would be too little data remaining for a scan - scaler yields black = 6.4 red = 9.2-1 green = 9.2-2 blue = 7.9 - the data sets are consistent with a lot of scatter between them, presumably since >200kHz data are used - the 7.9 setting was not used in Nathan's Lumi study because of a mis-communication between himself and Junaid Next steps: - found a LD2 physics setting where the current varied from 20 to 60uA - will use this as a CoinLumi study - will try applying the boiling correction determined from scalers, as well as other corrections, to see if the yields are flat vs current Next Meetings ------------- - Thurs: June 18 @ 13:00 Eastern/11:00 Regina - PionLT will be first - this overlaps the Hypernuclear session in the Hall A/C meeting - Fri: June 19 @ 12:00 Eastern/10:00 Regina - we will continue where we left off - not everyone will be available, due to Juneteenth holiday in Virginia