Jun 6/24 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, Muhammad Junaid, Ali Usman, Nathan Heinrich, Zach Sullivan, Nacer Hamdi, Vijay Kumar York - Stephen Kay CUA - Casey Morean, Tanja Horn Virginia - Richard Trotta CSULA - Konrad Aniol Nathan and Zach --------------- PionLT Luminosity Studies - Zach now has Nathan's scripts working in his account - Carbon HMS Runs 16727-16737 - Accept/Total scaler count is low for <15uA, will need to change current cuts for low current runs. Then will need to recheck low current data - CPULT is very low ~81%, while TLT ~98% - Richard: suggested looking more carefully at what trigger is used - Nathan: things using ELREAL instead of ELCLEAN, will check - LH2 HMS Runs 16703-16712 - Again a problem w/ CPULT ~79% - No boiling seen up to 60uA, then suddenly down to 92% at 80uA (no Track), same for Tracked analysis - Scaler analysis looks good however - Carbon SHMS Runs 16738-16746 - CPULT looks good, gives hint on what may be wrong for HMS analysis - LH2 SHMS Runs 16759-16764 - boiling looks better here, so need to look again at HMS, they should be the same within errors - Scaler analysis: 98% at 80uA - No-Track: 95% at 80uA - Track: 94% at 80uA - Next Steps: 1) Zach will work on code for Efficiencies for PID cuts used in analysis - will look to see if there is any rate dependence 2) Look at what trigger is used for CPULT calc 3) Adjust hcana current cuts for low current runs - then replay data and look at results Junaid ------ PionLT Detector Eff Study - runs with HMS p<4.2 GeV/c - Cer_eff uses npeSum >1.5 cut, tighter cut on Calorimeter - Cal_eff uses tight cut on Cerenkov instead - Obtain CerEff=0.9981 CalEff=0.9981 - KaonLT had CerEff much less than CalEff: CerEff=0.9717 CalEff=0.9929 - interesting that CerEff are so different between the two experiments - Tanja: when you applied tight cut on Cerenkov, did you do that to define the sample on the calorimeter? - Ali: CerEff is likely different from KaonLT due to different cut value used (1.5 vs 2.0 npe). KaonLT used nepSum>2 because that was needed in the Physics analysis. - *NB* You should do a quick check of 3-4 physics runs at different settings to make sure you don't need a higher cut PionLT Heep Study - finalized OOP offsets, corrected beam energies - there was some confusion on implementing momentum offsets - verified how the offset is applied in hcana, offsets need to be entered as %P. This means the P-offsets applied by Vijay are not done correctly. The effect will be small since his P-offsets are small, but should be checked as a systematic. - Heep comparison plots (before vs. after offsets) - PMZ, EM worse - PMX, PMY, W improved - Richard: similar behavior to what he saw - confirmed that simc-reconstruction script was used - Table of shifts between Data and SIMC (after offset vs. expected) - PMZ shifts in opposite direction than predicted by GH's program - need to look closer at whether to ADD or SUBTRACT offset - *NB* Garth: The HeepCheck program says dp_m(par) is correlated only with dp_p so the sign of the dp offsets should be checked Vijay ----- - Met with Richard, Ali yesterday to discuss systematics, Richard will give more details - Vijay is working on MM Cut-Dep study - will modify cuts by +/-2,4,6,8 MeV from standard 980 MeV MM cut - needs to subtract obtained cross section from that obtained with standard cut and tabulate the differences vs. t-bin Richard ------- - gives some info on using Globus for file transfer from JLab KaonLT LT-separations - simplified the functional form for sigL, sigT: - sigL=(p1+p2*log(Q2))*exp(p3*|t|) - sigT=(p5*(|t|/Q2-1)*exp(p6*|t|) - after 1 iteration, sigT did not change too much for Q2=3.0, W=3.14, so optimistic that on right track - tried to work on Q2=2.1 L/T-separations - the low epsilon diamond is quite small, corresponding to a relatively large delta-epsilon - this means there will be smaller error magnification for sigL, but at the cost of low epsilon data have poor statistics. Hopefully they will balance out in the final analysis - low epsilon stats are too low to be sure the functional form is good, etc. - will go to higher Q2 and then work down from there Summary of Random Systematics Discussion w/ Ali, Vijay Acceptance - vary geometrical cuts PID - vary PID cuts - HGC will drive K+ studies - separate studies needed here for every analysis, since backgrounds and cuts vary Tracking - compare effs for different algorithms, tracking parameters Kinematics - adjust offsets Radiative Corr - turn on/off radcor flag in SIMC Model Dep - vary input model - Garth: in pi-/pi+ analysis we set LT=TT=0 and extracted new cross sections without iterating - Tanja: Fpi-2 took a more gentle approach, used different models with iterating Nacer ----- KaonLT Heep Study - presented Data and SIMC cuts, corrections for 2 beam energies - 3.8 GeV Data/MC Yield ratio = 1.02 +/- 0.005 (stat) - 4.9 GeV ratio = 1.046 +/- 0.004 - both results very similar to Richard's, although analysis is different - *NB* Ali: The CerEff is calculated for >2npe cut, while Nacer is using >1.5npe cut. The cut and efficiency need to correspond to each other, so this needs to be checked. - We see from Junaid's results that the difference in CerEff is about 3%, so this might explain most of the ratio difference from Unity. Nacer and Junaid will discuss. Ali --- piDelta MM Shape Study for additional settings - Q2=3.0, W=3.14 - exluding (t,phi) bins from fit if low statistics or if MM fit fails - Center SHMS, high -t: Two bins (135