Feb 8/24 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 - Garth Huber, Ali Usman, Muhammad Junaid, Nacer Hamdi CSULA - Konrad Aniol York - Stephen Kay JLab - Dave Gaskell CUA - Richard Trotta, Tanja Horn Junaid ------ Errors on Tracking Efficiencies for Heep singles data - found the error in the calculation - data is replayed, will be looking at the results soon Richard ------- SIMC Weights - last week's issue was due to weight not being applied to SIMC yields - with this fixed, the 10^6 factor is no longer needed - now getting Data/MC ratios of 0.2-0.5 SIMC Missing Mass - last week reported a very long K+Lambda radiative tail, the opposite that was found for the pi+ analysis - Dave looked at RT's input files, and found that the wrong K+ decay length was used - 780.4cm was used instead of 371.2cm (i.e. pi+ value instead of K+ value) - SIMC would have generated the correct K+ decay products, but with the wrong probablity - the fact that the user has to input the correct decay length (instead of it being selected automatically since SIMC already knows it's handling K+ decay) is a historic artifact from Dave Koltenuk days - a second issue was that MM was not recalculated for SIMC events by the recon_hcana_script - with these corrected, the K+ radiative tail agrees better with the data, of course the data are still subject to change as well, until the PID cut study is completed K+ PID Studies - investigating pi+ and proton leakthrough into K+ sample - selected three different MM regions: MM<1.05 (should be mostly leakthrough protons) MM>1.16 (will contain leakthrough pi+ as well as real K+) K+Lambda region is 1.063NPE accepted now: events with >4.5NPE accepted - still need to adjust HGC hole cut - HGC optics were adjusted between low and high epsilon runs, need larger hole cut for 10.6 GeV data - MM>1.16 region, again look at Aerogel - will try 4.5NPE cut, maybe need 4NPE if cut is too restrictive - need to apply same Aerogel cut to all MM regions Data/MC Yield Comparisons - looking at Q2=2.115 yields with different MM cuts - ratios are closer to 1 with 1.06