Apr 13/23 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 - Ali, Alicia, Love, Junaid, Vijay, Garth CUA - Tanja, Richard FIU - Pete At GHP: Stephen, Nathan, Dave G Regrets: Julie, Jacob Richard Updates --------------- PID investigation - now doing a proton subtraction, but normalizing to the beam charge - getting a large over-subtraction of the data - GH: need to normalize to the size of the omega+p peak, not the charge - the idea is to use the data to understand the MM-shape of the proton leakthrough - the efficiency of the proton cut can be low, need a clean proton sample to be sure you aren't subtracting Kaons - the differing cut efficiency for K+ (with leakthrough) and protons (with minimal contamination) can be large, so normalizing only to beam charge won't work - deal with pion leakthrough subtraction the same way, normalizing to the pi+n peak - Ali and Richard meeting tomorrow at 16:00 Eastern to discuss PID Lumi Issues - no report today, will wrap up loose ends soon Ali Updates ----------- Pion PID study for all Q2>2.0 data, five settings in total - uses HGC to remove K+ leakthrough (keep NPE>1.5 events) - other cuts: acceptance, e-pi cointime, aerogel - analyzed so far: low epsilon (spring 2019), high epsilon (fall 2018) still running - MM spectra look clean, even up to Q2=5.5, looks like no K+ leakthrough subtraction will be needed, which is good news - GH: it will be important to study PID cut efficiencies as well, so that we are sure we aren't using a cut that leads to a large systematic uncertainty - AU: HMS Cer+Cal have stable effs SHMS aerogel efficiency also good Tracking has rate-dep efficiency we will calculate run-by-run - The real issue is the HGC efficiency, no hole cut applied yet - need to implement the HGC hole cut, meeting tomorrow will discuss this - two possibilities: a) divide HGC into 2 sections, remove hole with eff<75-80%, correct the rest for inefficiency b) divide HGC into 3 sections, remove eff<50%, correct 50-80%, 80-100% regions separately - it would be easier to implement 2 sections, at least for pi+ analysis but we need to do study to check - also need to apply same hole cut to SIMC - RT: we have the algorithm from Peter B, need to implement it - once the HGC hole cut is implemented, it will be interesting to see if Alicia notices any BSA difference with it, particularly the 2nd t-bin, which always looks anomalous - CoinTime also used to select PID - GH: maybe we need to apply a CT cut efficiency - use the HGC and aerogel to get a clean event sample, then plot CT for these events to get a better idea of a good cut for pi+, K+ analyses - so far, the CT plots that were made were without HGC cut, so the contamination from other channels is larger - the cleaner sample will enable the CT cuts to be optimized, particularly for K+ analysis, which has contamination from both pi+ and proton sides - TH: in Fpi-2 she did a study, and determined that a correction wasn't required. Need to do a similar study here. - CT resolution is worse than in Fpi-2 - For K+ almost certainly we need to apply a correction - For Vijay's low Q2 pi+ analysis, the study needs to also be done, but should be quick and the correction small (if at all) - Ali will have to do separate studies for low and high epsilon data, due to differing conditions - GH: Also we should do a quick check if RF cut needed or not - AU should check if pi+ MM spectrum changes shape (particularly in Delta region) with and without RF cut - if shape does not change, irrespective of yield change, then RF cut probably not needed - K+ may be a different situation than pi+ Vijay Updates ------------- Data/SIMC plots for each t-bin - 8 t-bins, 16 phi-bins - mid epsilon at Q2=0.38 shown - Plots of Data/MC ratio versus phi-bin for each t-bin - see clear oscillations (interference terms wrong in model), but overall surprisingly close to R=1 - GH: don't worry about the ratios for now, we need to be check instead if the code is working properly - for example, do the error bars propagate correctly from one SHMS setting to combined 5 SHMS settings - at higher -t, we see phi-bins which have much worse statistics than others. This is presumably due to incomplete phi-coverage at higher -t, but we should be sure - plot R vs phi-bin for each SHMS setting separately, and compare to the combined phi distribution to see if it all makes sense Shows a few sample SHMS xptar, yptar plots - Green=Data, Blue=SIMC - general agreement looks good - still working on other plots - GH: you will find it more convenient to make a PDF of several plots on a page, sorted by theme - this will let you more quickly investigate if things are looking okay as you do the iterations Next 2 week plan is to finish the plots and initial yield study EIC Meson WG Discussion ----------------------- - TH: next meeting is Thur April 20 @ 9:00 Eastern - we should discuss next plans, including a future paper - GH: has some questions on how new ePIC WG structure will work - seems to be more detector focused, less on the physics than before - in that scenario, the Meson WG will become even more important - should include JLab 22 GeV as well as 2nd detector issues, not just ePIC Next Meeting ------------ - Thur Apr 20 @ 16:00 Eastern/14:00 Regina/13:00 Pacific - PionLT will go first