Feb 22/24 PionLT/KaonLT Analysis Meeting Notes ---------------------------------------------- (Notes by GH) Today: PionLT will be discussed first Please remember to post your slides at: https://redmine.jlab.org/projects/kltexp/wiki/Kaon_LT_Meetings Present ------- Regina - Nathan Heinrich, Garth Huber, Ali Usman, Alicia Postuma, Muhammad Junaid, Nacer Hamdi CSULA - Konrad Aniol CUA - Richard Trotta, Tanja Horn York - Stephen Kay FIU - Pete Markowitz Nathan ------ Writing Lumi analysis script for PionLT - modifying script from Richard, which always assumed an active HMS and SHMS trigger for each run, as some PionLT Lumi scans were single arm only - had to make similar edits earlier for CoinLumi script, so confident of the needed changes - edits made, still testing Script for plots for SHMS NIM paper - started to modify old plotting script - looked briefly so far at the draft NIM paper text - once the plotting code has been run, will look up needed details for the paper Junaid ------ PionLT efficiency studies - investigating outlier runs identified last week, about 30 runs in total - will make some decisions soon on which runs to discard - then will post efficiency slides on RedMine Ali --- SIMC resolution study - on hold until Alicia finishes HMS delta-correction study Setting up for pi+n LT-analysis - replayed 3 of 5 settings so far (both epsilons) - of these, analysis completed for 2 of 3 settings - will give Richard clean pi+n data for subtraction - updated SIMC w/ physics_iterate.f model - compared to Vijay's code, almost identical except for different Q2-settings - looking at Richard's LT-sep scripts, hoping to have some initial ratios soon Info re HGC cut issue - no HGC cut intended to be used for pi+n analysis, get a small K+L leakage, but in MM region well above pi+n - this means pi+n analysis will also not need an HGC efficiency to be applied - on the other hand, pi+Delta0 region is affected by K+L leakage, and will need an HGC cut as well as an HGC efficiency to be applied - the pi+ sample for Richard will not have an HGC cut applied - will give skimmed ROOT files w/o HGC cut to RT, he will have to apply the HGC cut before subtracting pi+ leakage sample from K+ data Richard ------- Comparing SIMC model to preliminary data - looked at 4 of 6 settings (including Q2=0.5) - Q2=0.5 has lots of issues that he will flag for Nacer to eventually look at - standard.kinematics issues: - need to confirm that CoinTime offset is set correctly for EVERY run - SHMS_RF_Offset was also not set for some low Q2 runs Initial look at Q2=2.115, W=2.95 - all LT, TT terms set to zero for now in model - sigL model: adjusted exp(|t|-0.2) factor to exp(|t|+0.2), seems to give more stable ratios vs t - sigT model: compared p5+p6*log(Q2) with alternative p5*log(Q2)+p6/Q4 - also compared to Tanja's global K+ analysis in PRC 85, 018202 (2012) - checked W-factor and sigT models in this paper - W dependence: tried changing W-factor=1/(W2-Mp2)^2 to 1/(W2-Mp2)^3 - Tanja's paper has the power as 2.5 - when changing the W-factor, found that the sig_UNS expt error bars changed a lot, which should have not happened - this indicates a coding error that needs fixing - then tried sigT=p5/(1+p6*Q2) and old W-factor - manually changing p5 from 120 to 25 gave better ratios - doing things by hand right now, instead of using MINUIT to get new params Initial look at Q2=3.0, W=3.4 - same procedure, changing sigT and sigL factors - lowering sigT p5 param improves ratios, just as at Q2=2.115 - *WARNING* data have NO MM-cut applied at all, not only do the exp yields contain pi+ and proton leakthrough, they also include all K+ contributions from inclusive spectrum above Lambda peak - right, now sees a weird phi Left-Right asymmetry in the data - the experimental yields will CHANGE SIGNIFICANTLY once Richard has a clean sample - Ali offers to generate for Richard also a clean proton sample for subtraction Initial look at Q2=3.0, W=2.32 - looked at using W-factor with ^3 exponent - getting negative sigL for lowest -t bin, CAVEATS in data as above Compared initial results vs x_B - early indications that a systematic change in the model vs x_B will be needed, will be interesting if this holds up in more thorough analysis GH: as a reminder, we will eventually have to look again at the residual Q2-dependence of the Heep-Coin ratios, and resolve this issue before we can finalize the data and publish - this should happen after Richard graduates Alicia ------ Implementing HMS delta-correction, hsdelta_NEW=hsdelta-p0*hsxpfp - took MM calc from Richard's reconstruction script and implemented calc for data - as a check, compared new MM calc w/p0=0 to old MM calc - overall very similar, but a slight difference between them - plot difference in #events vs Mx, most pi+n events within +/-2 MeV compared to old MM calc - best guess is that there is some rounding error difference in the HMS momentum calc compared to hcana when applying offsets - GH: as a coding check, can try comparing old and new MM w/o offset - then applied Dave's p0 values and compared the old-new data - MM gets wider instead of narrower, something still seems wrong - GH: suggest to make a plot of hsdelta_NEW vs hsxpfp to see what kind of correlation you get, should be a straight vertical band if applied correctly - Alicia will send her script to Richard for review Nacer ----- Low Q2 KaonLT calibs - finished DC and Hodo timewalk calcs - pull request to GitHub was accepted - did a full replay, including all of Ali and Richard's improvements - plot of EDTM vs Coin_trig_rate - sees sharp drop off above 2.7kHz trig rate, as expected, due to buffered mode data acquisition (good news) - plot of COIN_CPULT vs COIN_trig_rate - similar behavior, looks good - plots of HMS(e), SHMS(pi) SING_TRK_Eff vs S1X hodo rate - no HMS outliers - a few SHMS outliers that need investigation To Do: - check other plots - move to K+ PID - also should get Lumi scripts from Richard and look at Low-Q2 Lumi scans Next Meeting ------------ - Thur Feb 29 @ 15:00 Eastern/14:00 Regina - KaonLT will go first