Feb 27/25 PionLT/KaonLT Analysis Meeting Notes ---------------------------------------------- (Notes by GH) Today: KaonLT will be discussed first Present ------- Regina - Garth Huber, Ali Usman, Alicia Postuma, Muhammad Junaid, Nathan Heinrich, Nacer Hamdi FIU - Pete Markowitz Ohio - Julie Roche Virginia - Richard Trotta JLab - Dave Gaskell Alicia ------ pi+n BSA revisions - please send your comments ASAP! - comments received so far from Dave Mack and Vijay - minor changes will be made to one figure and the text Simonetta Liutti comtacted GH that she is starting to work on pion GPDs and requests data - Alicia is helping put together a spreadsheet of sig0,L,T,LT,TT,LT' cross sections for exclusive pi+,pi-,pi0,K+ reactions - Julie also received a request for pi0 data, will coordinate with Alicia - Simonetta also requested exclusive eta data - Pete will make some inquiries regarding the CLAS eta data tables Vijay ----- Unfortunately, I cannot make the meeting today. I'm changing my apartment and fully busy. However, I've decided to report my update through email. 1) I've implemented the new diamond cuts in the analysis that determined for the Q^2 =0.42 GeV^2. 2) I've started the changing t binning for the analysis. It's a critical to have similar statistics (including all settings) in all t bins. 3) I want to check the ftave equation in the SigT cross-section for this analysis. Hopefully, I'll have some plot from data and MC comparisons in the next meeting. Richard ------- KaonLT High Q2 L/T-separations - Q2=4.4 after 10 iterations using same parameterization as last week - highest -t bin has oscillations in R=Data/MC but lowest -t bin looks flatter - GH: this indicates the parameterized t-dependence is probably different than the data at high -t - noted for some time that sigT is strongly negative for lowest -t bin - this has been traced to a single phi bin with tiny errors - if this point is removed, sigT is not so negative - will do some investigation of this point, maybe there's some pion contamination sneaking in that is driving the errors - Q2=5.5 after 10 iterations, same parameterization - high epsilon has large R=Data/MC while small epsilon has small R - similar issue with negative sigT in lowest -t bin, will check contamination here as well - Pete: Q2=4.4, 5.5 both have nearly zero sigL,T for -t~0.75, is the cross section really nearly zero there, seems puzzling that the cross section is so small there - Richard: not sure yet that's so believable. Notice also that LT,TT are fairly large for these bins Junaid ------ PionLT Heep analysis - GH followed Dave's idea from last week and made two new sets of offsets 1) global fit of 9 settings from 5.5-9.9 GeV beam energy: dthe 0.7000 dpe 1.0000 dthp 1.8000 dpp -0.8500 dE: -0.3000 -0.2000 -0.2000 -0.2000 -0.3778 -0.1556 -0.6000 -0.4889 0.4000 2) fit of just 10.6 GeV setting, where the HMS and SHMS angle offsets are taken from (1) and only new momentum and beam offsets are fit: dthe 1.5000 dpe -3.2000 dthp 1.4000 dpp 1.7000 dE -1.0000 units are 0.1% for momenta/energy, 1 mrad for angles - Heep distribution Data:MC comparo using these offsets - 5.5-9.9 GeV: PMx,PMy,W distributions overlap better - PMz,EM not so much improved in comparison to "no offset" - 10.6 GeV: PMz,E agreement is better than offsets used last week from 5.5-10.6 global fit - Junaid takes the pSHMS offset from the 10.6 fit and apply it also to 5.5-9.9 GeV, keeping all of the other offsets the same - i.e. only pHMS will be different between 10.6 and the other beam energies (presumably due to effect of saturation at HMS=5.8 GeV/c) all other HMS,SHMS offsets the same. The beam energy offsets remain different for every energy. - the agreement for PMz,EM is improved for all 5.5-9.9 GeV settings - then does an investigation of global pSHMS offsets from +1.0 to +5.0, finds that pSHMS offset of +4.5x0.1% gives noticeably better agreement for PMz,EM everywhere - the agreement between Data and MC distributions is now quite good - Dave: puzzling that the Heepcheck analysis didn't give the correct pSHMS offset - Garth: the offset fitting program predicts data-MC residuals for the obtained offsets - the observed residuals are much worse than predicted, particularly for PMz,EM - only reason can think of is that the Heepcheck program uses only the centroids in its analysis, not the full data distribution - looked over the Heepcheck program, everything looks correct in its evaluation of the kinematic derivatives - Junaid will apply these offsets to the physics data - will need to recheck the 10.6 setting after new HMS delta offset for 5.8 GeV/c setting is received, but hopefully that effect is small Nathan ------ - no report, has been sick most of the week Nacer ----- KaonLT Q2=0.5 analysis - new diamond cut, checking vs data for all SHMS settings at low and high epsilon - trying to find a cut that works for both Lambda and Sigma final states - plot W-Q2 after all cuts, including MM, dummy subtraction, etc - cut looks very nice, will move next to t-binning - for Lambda, will try 12 phi-bins, 6 t-bins - Richard: tried to have >1000 events/t-bin, summed over both SHMS settings at low epsilon, statistics were higher at high epsilon - Ali: Sigma stats are much lower than Lambda, you will need fewer t-bins for Sigma Next Meeting ------------- - Thur Mar 6 @ 15:30 Eastern/14:30 Regina - PionLT will go first - NOTE: on Mar 9 USA moves to DST, so we will need to move to 16:30 Eastern/14:30 Regina for the period March 13-April 10 - after that, we can return to 15:30 Eastern for the convenience of our USA colleagues