Jan 15-16/26 PionLT/KaonLT Analysis Meeting Notes ------------------------------------------------- (Notes by GH) Today: KaonLT will be discussed first Thursday: Present ----------------- Regina - Garth Huber, Muhammad Junaid, Alicia Postuma, Nermin Sadoun, Nacer Hamdi CUA - Sameer Jain, Tanja Horn, Chi Kin Tam Virginia - Richard Trotta Ohio - Julie Roche FIU - Pete Markowitz Chi Kin ------- KaonLT High Q2 LT-sep - diamond cut adjustments for: Q2=2.1 W=2.95; Q2=3.0 W=3.14; Q2=4.4 W=2.74; Q2=5.5 W=3.02 - compared data and SIMC for high, low epsilon, take the minimum overlap region - previous studies only looked at center SHMS settings, now overlaying left-right-center SHMS for both epsilons, and made some adjustments Q2=3.0, W=2.32 - found an issue with high epsilon RIGHT setting - diamond is smaller than center & left SHMS, missing low W part of diamond - will reduce the size of the diamond for all settings at this Q2-W to compensate - Richard: this was the very first KaonLT setting taken, something may have been off - *NB* will take another look at the run kinematics to see if we can identify what caused this - Q2=4.4 new iterations - compared with Richard's results from 11/06/25 - Richard had sigT ~8, while CKT has ~60 - *NB* Richard and Chi Kin will cross-check Sameer ------ KaonLT CoinTime Blocking - corrected all rates for BeamOnTime - had a question on whether the beam current cuts have been set correctly - looked at the run sheet target current, in some cases this was different than BCM2 value, which was then used - showed some plots of CoinBlock vs corrected CoinRate - trends with rate generally looked a lot better now - Q2=3.0 W=3.14: SHMS Right CoinBlock are low compared to Left and Center - Garth: it could either be that the rate is calculated too low and the point is really further to the right, or that the CoinBlock is wrong and should really be higher - *NB* Tanja: SJ should check if the rate is too low, or if the cuts needed for the correction are off for this setting Nacer ----- KaonLT Q2=0.5 LT-sep - tried a variety of L/T parameterizations - the best Data/MC ratios are found with sigT = p1/Q2 + |t|**p2/(Q2+p3)**2 and L=LT=TT=0 - tried to add back a function for sigL, such as sigL = p4/Q2 + p5/|t|**p6 which results in the ratios getting worse - also, sigT has a drop in cross section at low -t and he hasn't been able to find a funtion which describes this while getting a good fit at low -t - Junaid: what do the kinematic plot comparisons look like? - Garth: more important than the stability of the Data/MC ratios is the stability of the resulting cross sections - *NB* please make a spreadsheet comparing sigL,T for a model w/sigL and a model w/o sigL and let's see to what degree the cross sections are stable - if they are stable within errors, and the kinematic plots look good, then that's good enough. If the cross sections are not stable, then we need to figure out next steps. - K+ absorption correction - Junaid helped getting the Geant4 code to work - removed NGC, the other cuts in the script seem applicable - get a corretion of 4.2% at 2.5 GeV/c - *NB* it would be good to cross check with Vijay's correction - using Nathan's LH2 boiling factor - *NB* should cross check it with what Chi Kin/Richard use - Sameer has KaonLT Q2=0.5 runs, will look at CoinBlock for these setting - Nacer will communicate on cuts and other issues Alicia ------ KaonLT u-channel background subtraction - found a work around for the weird Pythia issues at Q2=3.0 W=2.32 - double bump in Python MM distribution - this setting also has worse MM resolution than the others - previously, found that adjustments to Pythia input parameters made no difference - however, applying acceptance cuts makes the MM distribution smoother - plots of ssxpfp,ssypfp for MM<0.9(rho-omega) and MM>0.9(phasespace) regions show some interesting correlations - the idea would be to adjust the ssxpfp cut to get better agreement with MM distribution shape - change to ssxpfp<0.02 instead of <0.04 - resulting Pythia MM distribution is smoother - Note: the previous MM upper edge issue (Data and MC had different limist) was traced to the diamond cut and fixed - *NB* Garth: to confirm that applying a different cut to Pythia MC than to data and other MC doesn't create new issues, we should look at the Data vs MC comparison of variables other than MM - from the MM fit of MC to data, find the MC scale factor - apply this scale factor to plots of other variables - make plots of subtracted data vs omega MC, and plots of data vs sum of normalized MCs Firday: Present --------------- Regina - Garth Huber, Alicia Postuma, Nathan Heinrich, Nacer Hamdi, Nermin Sadoun, Vijay Kumar JMU - Gabriel Niculesu, Ionana Niculescu Glasgow - Kathleen Ramage, Rachel Montgomery CUA - Sameer Jain, Tanja Horn, Chi Kin Tam Virginia - Richard Trotta FIU - Pete Markowitz Richard ------- KaonLT High Q2 LT-sep - Data/MC plots for Q2=3.0 W=2.32 and Q2=5.5, using exactly the same parameters and functions as Q2=4.4 - ratios are surprisingly close to 1 - uncertainties now include background subtraction uncertainties, so are much larger in some cases - errors look quite large for larger Q2 settings, need to reduce t-binning and change upper and lower t-ranges - Q2=4.4: need to go from 4 to 2 or 3 t-bins, also 15 to 9 phi bins - Q2=5.5: need to go from 2 to 1 t-bin, reduce phi bins too - kinematic plots: Q2=4.4 HMS-delta has some disagreement in shape, the others are fairly reasonable To Do: - need to deal with the diamond cut identified by Chi Kin - need to address Q2=4.4 cross section discrepancy between CKT and RT Vijay ----- PionLT Low Q2 systematic studies - changing CoinTime cut by +/-10%, last week found that low epsilon sigUNS was much more sensitive than mid and high epsilon - given this is sensitivity, Garth asked VK to look at this vs t - obtained separated cross sections for the +/-10% cut variation - Garth had asked to try with no iterations to model - Q2=0.375: sigL changed by 18% - *NB* Tanja: suggests to do 1-2 iterations to see if this sensitivity remains - shows some fits of PKT model to Q2=0.375,0.425 data - model shows a turn over in sigL at lowest -t that is not exhibited by data - we have some discusion about this - more studies are clearly needed to assess the reliability of the model to these kinematics Nermin ------ PionLT LD2 setting up for PID studies - created a run list of LD2 data for all 4 beam energies - had some issues submitting iFarm runs, which has been fixed - produced ROOT files were corruped, need to look again at production scripts Kathleen -------- PionLT setting up for data analysis - looking at previous Heep data replay raw trees - using Junaid's script: singyield_heep.py for Run 10600 - looking into why H_gtr_xptar,yptar are missing - will compare W vs yield for SIMC and Coin Data Next Meetings ------------------ - Thurs: Jan 22 @ 16:00 Eastern/15:00 Regina - PionLT will go first - Fri: Jan 23 @ 11:00 Eastern/10:00 Regina - we will continue where we left off