Sept 26/24 PionLT/KaonLT Analysis Meeting Notes ----------------------------------------------- (Notes by GH) Today: KaonLT will be discussed first Please remember to post your slides at: https://redmine.jlab.org/projects/kltexp/wiki/Kaon_LT_Meetings Present ------- Regina - Garth Huber, Ali Usman, Alicia Postuma, Muhammad Junaid, Nathan Heinrich, Nacer Hamdi CUA - Tanja Horn, Casey Morean Virginia - Richard Trotta Ohio - Julie Roche JLab - Peter Bosted Richard ------- KaonLT Analysis - investigating MMpi shift issue from last week - looked at hcana, CoinTime offset - waiting on Vijay to send his ROOT files, hasn't heard from him in a while - Tanja: an open collaboration requires access to ROOT files and the code used to generate them, as it required for validation of results - we really need to communicate with Vijay on this Alicia ------ Addressing BSA referee comments - pion PID purity and efficiency - applied generous HGC hole cut and HGC_npe>3 cut to select cleaner sample of pion events - found evidence of a small proton contamination at low MMpi - applied same MMpi<0.91 cut as used by Vijay - new results with MMpi<0.91 cut - mean t-value per bin shifts slightly - two BSA points move about 0.5sigma, others barely move at all - lowest -t bin at Q2=3.0, x=0.40 shifts upward - second highest -t bin at Q2=3.0, x=0.25 moves a bit too - planning to include this variation as an additional cut dependence systematic uncertainty - pion efficiency: - denominator: physics(includes AERO_npe>3 cut) * HGC_hole * HGC_npe>3 - numerator: remove AERO_npe>3 cut - efficiency=97% - Peter: this sounds reasonable - pion purity (first estimate): - denominator: physics(includes AERO_npe>3 cut) * HGC_hole * HGC_npe>0 - numerator: same but HGC_npe>3 cut - this really sounds more of an efficiency, not a purity - Ali: take a look at pion purity discussion in Bircu's thesis - Peter: purity depends on kinematics, while efficiency does not - after applying a tight MMpi cut, would expect inpurity to be very small - will need to think more on exactly how to reply to referee on this Nacer ----- KaonLT Heep analysis - setting up analysis for Heep singles - Junaid had a Heep singled analysis framework from PionLT online analysis - this has been adapted to KaonLT, replaying 3.8GeV data now - 10.6GeV Heep CoinTime plot - when completely removing CoinTime and HMS_beta cuts, the yield changed 10% - will review cuts on log scale to make sure they're appropriate Junaid ------ PionLT Heep analysis - effective charge uncertainties now included - SHMS_beta plot - get some zero bin entries, if place beta>0.2 cut, Heep ratios drop a few percent - Peter: in hcana, the beta calculation requires 4/4 planes hit, otherwise beta=0 is assigned, the #entries at beta=0 reflects the difference between 4/4 and 3/4 efficiencies - Peter: SHMS_beta cut not useful for P_SHMS<2 GeV/c, and even then, you can deal with the same PID info with CoinTime and RF cuts - Peter: recommends to ignore SHMS_beta, just check to make sure peak is near 1 to be sure the timing corrections are good - Tanja and Garth agree, don't apply a SHMS_beta cut, if you do, you would have to correct for 4/4 efficiency to get the same result - proton absorption correction - Peter: raises the same issue with protons rescattering and still causing a trigger that was raised earlier - we discuss putting together a simple Geant4 simulation that would do a better job of estimating the correction than the simple spreadsheet - would only need thin slabs of material to get the correction, not detailed geometry - the spreadsheet already includes relevant information - Alicia volunteers to work on this after her comprehensive exam is done - SHMS-3/4 efficiency - consulted with Mark on this, waiting for more information - Peter: agrees that the efficiency should be high Next steps - will work on SHMS pion PID and setting up pion detector efficiencies Nathan ------ PionLT Lumi studies - first plots from 2021 Coincidence scan, Runs 12218-12258 - some crazy CPULT so clearly needs more work - replaying 2022 Coin lumi data Ali --- Overview of DNP talk on piDelta BSA - shortening talk to fit into 10+2 format, was set up for 12+5 - will include CLAS pi-Delta++ results - will circuate draft this weekend, talk is on Oct 8 Next Meeting ------------- - Thur Oct 3 @ 16:30 Eastern/14:30 Regina - PionLT will go first