Aug 28/25 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, Nathan Heinrich, Vijay Kumar, Nacer Hamdi, Muhammad Junaid CUA - Chi Kin Tam, Tanja Horn, Sameer Jain Ohio - Julie Roche Nacer ----- KaonLT Q2=0.5 LT-sep - went back from Fpi-2 pi+ to sig_factorized_2007 K+ parameterization - this is based on Q2,W-dependence of Bebek & Brauel data, an update by Tanja of Koltenuk parameterization - this parameterization includes a fixed T/L=2 ratio - has a different W-factor than Fpi-2, retaining Fpi-2 W-fac for now - when using initial params w/no fit (IT00) - Data/MC~2 for both low and high epsilon, good agreement between Data & MC for variable histos except for this normalization factor - found that reweight script does not fully reproduce SIMC output, still investigating - Tanja suggests there may be an issue with tmin dependence in the t-factor i.e. t-fac=exp(p*(t-tmin)) - also will look into changing W-fac to the sig_factorized_2007 version Junaid ------ Q2=3.85 LT-sep (pi+) - changed sigL form from Fpi-2 pi+ to P.Bosted parameterization - includes a fixed parameterization of Fpi(Q2) and pole term in sigL form - when using initial params w/no fit (IT00) Data/MC ratios~6 - does 1 iteration allowing sigL params to float but keeping sigT frozen, get ratios~10 - IT01, instead of fixing sigT, let p1,p2 float - all plots look good, Rosenbluth fits to sig_UNS, fits of params to sigL,T, data-MC shape comparisons - however, the normalization is way off, the Data/MC ratios went up to ~30 - Garth: strongly suggests something is wrong in the code, before the iteration SIMC was too small (compared to data) by ~6x. - After the iteration, SIMC went down by 5X instead of up 5X. - Maybe something is backwards in the code, such as a Data/MC ratio being inverted by mistake as MC/Data? For sure, something is not consistent. Chi Kin ------- KaonLT Q2=3.0, W=3.14 analysis - carefully going through Richard's code and doing checks - found that the MM shifting algorithm needs fixing - RT fit a Gaussian to a too-wide region around the Lambda peak, and the long radiative tail was throwing off the fit - changed to a Gaussian with a flat bkd fit, giving a much better description of the peak value - Garth: the peak shape is not Gaussian due to the radiative tail, suggests to restrict the fit to 1.100, and HMS/SHMS acceptance cuts when making plots - Nathan also found an oversight, was cutting on HTrig1 instead of PTrig1 - CTime.CoinTime_RAW_ROC1,2 distributions are narrower now, with simpler features - both ROCs behave similarly, will be using ROC2 - will evaluate a CoinBlockingCorrection from these plots - the region 30-130 has beam pulse structure, outside this region the structure is more random - Garth: suggest first to sort these plots by rate, so you can see how the features change as rate is increased, the coin blocking correction should be negligible at the lowest rate - new set of Lumi yield plots vs current and rate - new tighter cuts (after discuss w/Mark) didn't make any difference - in comparison to plots from before RefTime study, the spread vs Rate is tighter, particularly when plotted vs CoinHMSRate and CoinRate - when investigating outliers, found that CoinTime offset was wrong in some cases - Junaid's new CT offsets use ROC2, while Nathan was using ROC1 by mistake Garth ----- BSA PLB revised Fig 4 - Tanja and Julie found the plot to be confusing - GH will contact Stefan Diehl about standard deviations of CLAS12 data - Julie: instead of all data, one possibility is to just show a selected version, showing how the experiments differ near x=0.25 Next Meeting ------------- - Thur Sept 4 @ 15:30 Eastern/13:30 Regina - PionLT will go first _ not everyone will be available, because of teaching conflicts - please fill out the poll to select a new time starting week of Sept 8 https://www.when2meet.com/?31948498-x2KTs