Aug 29/24 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, Alicia Postuma, Ali Usman, Nathan Heinrich, Muhammad Junaid, Vijay Kumar, Zach Sullivan, Nacer Hamdi York - Stephen Kay JLab - Dave Gaskell FIU - Pete Markowitz CUA - Casey Morean, Tanja Horn Virginia - Richard Trotta Nathan & Zach ------------- PionLT Lumi studies - last week it was discussed using TLT from CPULT & ElLT instead of EDTM - ElLT calc from 55ns*(Total Rate) - Plots Red: EDTM Blue: CPU method - SHMS Carbon Runs 16738-16746 - w/EDTM, a small yield rise w/current, 2 outlier runs - CPU method: LT used if it disagrees w/TLT >1 sigma yield is flat within errors - HMS LH2 Runs 16703-16712 - CPULT~80%, must be an issue with how it is calculated - Dave: *NB* you can infer the CPULT from other info in the report file - it should be #ADC-events/PreTrig-Scaler-events - maybe the calc is pointing to the wrong PreTrig - can calculate by hand to check - quickly runs through slides for next week's Quarterly Analysis Mtg on BCM calib, looks good Junaid ------ PionLT SHMS-3/4 Hodo Effs - some runs have low eff ~85-87% - plots of single plane eff vs 3/4-Trig-Rate and S1X-Hodo-Rate - 1st plane: ~99% - 2nd plane: one set at 95-96%, and other at ~98% - 3rd plane: two trends: flat at 78-82%, exp drop 98-80% - 4th plane: two trends: flat at 80-90%, lower trend 65-70% - Dave: *NB* suggest plot of Eff vs Momentum - quartz bar effs are lower at low momentum - makes it difficult to test 3rd plane eff when 4th plane inefficient - Dave: *NB* check the slop parameters in hcana on track projection to planes in param file - assumes there is a valid trigger and a vaid track - looks at each plane in succession and uses track selection to find out which hodo bar should have been hit, and then checks if that hodo fired - maybe the track is pointing to the wrong hodo due to multiple-scattering - if the track slop parameter is too tight, then the hodo is not counted, leading to a too-low efficiency - Dave: *NB* it would be helpful to see if there is a version of this efficiency calculation with PID cuts - i.e. in the 6-GeV era, we had multiple calculations of efficiencies: overall, pions only, protons only, electrons only - not sure if this was carried over into the 12-GeV era code or not - Dave: *NB* checks the code and finds there is a hardwired Cherenkov cut in the hodoscope efficiency calculation, CERCUT - it might be inappropriately set - if this cut value is changed, hcana needs to be recompiled - SHMS_Hodo-S1XY, S2XY effs are much higher, >90% - Dave: these were for an STOF OR test, not so relevant anymore PionLT HeeP - data have pi0 contribs - calculate Exp/MC ratio w/ and w/o pi0 cut, MM<0.1 GeV - 8.5 GeV data: Ratio goes from 1.136 (w/o cut) to 1.028 (w/ cut) - implemented Ali's Drift Chamber resolution param in SIMC for this analysis Nacer ----- KaonLT HeeP - looking at 8.2 GeV data, which have worst Exp/MC ratio - ElLT calc: - using 55ns*Rate >99.9%, where HMS-ELREAL+SHMS-3/4 ~ 4kHz - using ElLT from EDTM and CPULT: 95.6-99.6% - EDTM: R=1.126+/-0.006 w/ElLT: R-1.111+/-0.006 - MM comparo - Change resmult=1.0 to 3.5 (Ali's resolution smearing parameter adjustment) - delta vs MM for SHMS, HMS - data shows a wider region (delta<0 SHMS, delta>0 HMS) than SIMC - pi0 background, place conservative cut >0.11 GeV, could have used >0.10 - with resolution tuning but no MM cut, still get an extra bump in delta - add MM>0.11 cut, the data-MC overlap is much better - R-1.027+/-0.006 - Ratios for the other Heep runs: 3.8: 1.000 +/- 0.004 4.9: 1.001 +/- 0.004 6.2: 1.019 +/- 0.004 6.8: 1.027 +/- 0.006 10.6: 0.930 +/- 0.005 w/o MM cut: R=1.043 - Overall, very good news, things much better than before! Well done Nacer! - GH: *NB* should investigate some MM cut dep - *NB* should also look at applying a proton absorption correction (John Matter's spreadsheet, but need to adjust cross section for specific momentum) - *NB* finally, need to estimate the systematic uncertainty in the Ratio, it won't change the Ratios themselves, but it will change the significance of the deviation from 1, and help establish our overall systematic uncertainty - this would include not only the systematic in the Exp yield, but also the systematic in the SIMC yield (Nacer already determined this is higher at 10.6, from elastic model dep) - Discussion about using old HMS Matrix Elements - Dave has found a systematic improvement between Data and MC comparison in XEM data when using 6-GeV era matrix elements (ME) - apparently these ME are not in the standard distribution, Dave had to find them from older code - it sounds worthwhile to check this with the Heep data, and if it is better, then we should also use it for the physics data (both KaonLT and PionLT) - *NB* Dave will send more information on what file to use Richard ------- Q2=4.4 LT-separations - in a separate meeting, Dave had suggested to recheck recon_hcana calculations - plots of xptar vs yptar, all cuts applied, for SHMS, HMS - also: delta vs delta - agreement of shapes between data and MC seems reasonable, although there are some binning issues with the data which hopefully will be fixed with improved plotting - Some weird results last week were due to SIMC using a different parameterization than the iterations, so params in one set of eqns did not work in the other set - that is fixed now, things starting to improve - the issue, however, is that ratios get stuck ~0.4-0.6 for all Q2 - Garth: strongly feel there is still an inconsistency in the code somewhere, Ratios must converge to 1, if the function is wrong, there will be weird shapes to the ratios centered around 1 - the good news appears to be that the bug seems to be the same for all Q2, so if Richard finds it once, it should be good for all settings - Vijay does not recalculate SIMC weights, he reruns SIMC every time, so checking against Vijay's version of this code is not very meaningful - *NB* Vijay can meet with Richard later next week, probably Thursday - will do a full replay of all data, including HeeP, to reproduce Nacer's work Ali, Alicia, Vijay ------------------ - no report this week Next Meeting ------------- - Thur Sept 5 @ 16:30 Eastern/14:30 Regina - KaonLT will go first - *NB* Please note the new time and new Zoom ID!