Dec 5/24 PionLT/KaonLT Analysis Meeting Notes --------------------------------------------- (Notes by GH) Today: KaonLT will be discussed first Present ------- Regina - Garth Huber, Nathan Heinrich, Ali Usman, Vijay Kumar, Nacer Hamdi, Alicia Postuma JLab - Dave Gaskell CUA - Tanja Horn Virginia - Richard Trotta FIU - Pete Markowitz Ohio - Julie Roche Richard ------- KaonLT Q2=3.0 W=3.14 analysis - shifted MM so that data and MC are consistent when MM cut is applied - fit top of peak w/Gaussian, both data and MC - shift was ~5 MeV, fairly consistent - if only a global MM fit was done (rather than by run) the shift is larger ~10 MeV due to outlier runs - reran all cut scripts over holiday to implement the MM offsets - also identified some bugs that have been fixed, a negative event filter for debugging purposes was mistakenly still in - rechecked pi+ leakthrough subtraction for each (t,phi) bin - pion leakthrough is much worse for the lowest -t=0.18 compared to second t-bin - pion leakthrough probably explains why the earlier L,T results resulted in a large increase in cross section for lowest -t bin - some discussion about t-binning, the lowest 0.15-0.21 -t bin has low statistics - Dave: suggests to raise upper limit of lower bin to increase statistical significance, other bins would then shift accordingly - might also reduce the number of t-bins, using a minimum of 1k events per t-bin (summed over phi, SHMS settings), 2k might be better? Next steps: - adjust t-bins - will recheck L/T-iterations, code was crashing due to MM misalighment issue - then will look at Q2=4.4 setting - aiming to circulate draft slides ~Jan 4 Vijay ----- Low Q2 PionLT analysis - started setting up for Q2=0.42 analysis - all data (both Q2) are replayed, and available - investigating issue with Q2=0.38 analysis, that L,T results are significantly lower than expected (Ackermann data) - did a quick comparison of iteration functions compared to default physics_pion parameterization, these differ by about ~2x for middle epsilon, not 10x - aiming to circulate draft slides early Jan Alicia ------ BSA paper rejected by PRL, 4th referee negative - referee B was polite but negative - referee D seemed to not understand some parts of the paper, the report will be helpful in seeing what parts we need to improve - in the end, the tigher PRL acceptance criteria seemed to be an issue - editor suggested we try PRD - PRD does have a letters section, slightly longer length limit than PRL - categories in PRC are a better fit for us than PRD - Dave suggests PLB - 2 years ago, transferred EMC paper from PRL to PRC, but it was still a hassle - general consensus that this is the best option - Alicia will provide a synopsis of what happened for collaboration info - will prepare a new version for PLB Ali --- - thesis writing - will circulate draft slides early Jan Nacer ----- KaonLT Heep singles - following up on ytar MC-Data comparo suggested by GH - found the correct variable, Richard helped a lot - has results for some energies, still waiting for others, prefers to wait for full results before distributing results - 10.6 GeV has significantly worse W-resolution than others - GH raises issue of SIMC higher beam energy spread, we're using the default beam energy spread for all energies, should we use a wider spread for 5-pass? - Dave: investigated beam energy effects for 22 GeV, found that spectrometer resolution still dominated over beam energy spread - finds a new paper Phys Rev Accel Beams 27 084802: 2E-4 beam energy spread at top energy HMS,SHMS resolution is ~0.1% - agrees we should in principle use a wider energy spread for 5-pass, but it won't solve this problem Nathan ------ - working on finishing up proton structure class - will get to Lumi studies next, would like to have them completed before Junaid gets back (Jan 15) Next Meeting ------------- - Thur Dec 12 @ 16:00 Eastern/15:00 Regina - PionLT will go first - Garth can't attend, Richard will take notes