Oct 23-24/25 PionLT/KaonLT Analysis Meeting Notes ------------------------------------------------- (Notes by GH) Today: KaonLT will be discussed first Please remember to post your slides at: https://redmine.jlab.org/projects/kltexp/wiki/Kaon_LT_Meetings Thursday: Present ----------------- Regina - Garth Huber, Nathan Heinrich, Muhammad Junaid, Alicia Postuma, Nermin Sadoun, Vijay Kumar CUA - Chi Kin Tam, Tanja Horn, BC Manoj JLab - Dave Gaskell Virginia - Richard Trotta Ohio - Julie Roche Richard ------- KaonLT - checking phi calculation in SIMC - SIMC version of phi_lab goes from -pi to +pi - if phi<0, add 2pi. It's important not to add pi to all angles, as this screws up the 0 to pi part. - thetapq, thetapqi - reconstructed and vertex theta_pq quantities - thetacm - vertex angle in CM frame - many thetacm values are zero or NaN even though other variables are fine - still investigating - Vijay: saw the same thing, seems that thetacm is not output for every event - Junaid: does not see this problem - *NB* it's important to add this variable to results_write.f in SIMC - check with Junaid for instructions, if needed - Peter Bosted's email about phi - Dave did a quick test, the difference between old and new phi calcs is very small, both definitions appear to be consistent Chi Kin ------- Q2=4.4 data analysis - comparing #counts after cuts w/Richard - purposefully removed pion and random subtractions, still have a yield difference - effective chage is same for Left, Center but different for Right - looks like some runs were missed in the replay - have not yet compared HGC hole cut effects Alicia ------ u-channel analysis - PYTHIA simulations - found that Pythia does a poor job for the Q2=3.0, W=2.32 setting - MM distributions have extra structures not seen for higher W settings - looked at correlations of MM with other variables - e.g. additional lines appear in MM vs hsyptar - it really looks like a resonance or some exclusive process is included - *NB* Garth: suggest to compare Pythia to data, perhaps the data have the same structrues at this W? - if not, then try comparing to Xphsp simulation, at this lower W the MM coverage of the simulatino might be sufficient Junaid ------ PionLT analysis - replayed all PionLT data after Nathan's new report files (for CoinBlocking corr) - will look into phi issue next Nathan ------ PionLT Lumi analysis - working on a write-up of the results, hopes to share a draft next week -- Friday: present --------------- Regina - Garth Huber, Alicia Postuma, Nathan Heinrich, Nermin Sadoun, Muhammad Junaid, Vijay Kumar, Nacer Hamdi York - Stephen Kay Glasgow - Kathleen Ramage, Rachel Montgomery JLab - Dave Gaskell CUA - Sameer Jain, Tanja Horn, BC Manoj JMU - Gabriel Niculescu Ohio - Julie Roche Virginia - Richard Trotta FIU - Pete Markowitz Nacer ----- KaonLT Q2=0.5 analysis - following up on last week's discussion about high sensitivity to phi-dependence when adding interference terms to LT-separation - compared phipqi to phipq from SIMC - for Center setting, distributions are fairly similar, except that big pekas in phi-dists are shifted away from 90deg, 270deg - for Left, Right settings, distributions are offset from each other by 180deg - *NB* this is because pi was added to all angles, instead: - for phi<0 add +2pi - for phi>0 leave unchanged - working on Sigma yields Gabriel ------- KaonLT - looking at CoinBlocking correction Sameer ------ KaonLT - showed plots for CoinBlocking correction - *NB* Nathan: need to get rid of weird peaks at -300 first, they look like they're due to a bad RefTime cut - look at T.coin.pTRIG1_ROC1_tdcTimeRaw, keeping in mind that triggers are different between KaonLT and PionLT pTRIG1(PionLT)=pTRIG4(KaonLT) - suggest to start by plotting the raw timing variables and selecting proper cuts - only after that is done should you select the cuts for the CoinBlocking correction - the wide cut needs to select the base of the full distribution Vijay ----- Summer 2019 PionLT analysis - CoinBlocking correction: using a 135ns window - correction varies 87%-98% plotted vs Run Number - *NB* Garth: please plot it vs CoinRate, so we can verify the correction makes sense - Nathan: if the correction is good, it should go to unity at zero rate - presents GH's fit of VGL model to initial results - sigT is much larger than Ackermann Q2=0.35 data - sigLT is opposite sign to Ackermann as well - Fpi-1 Q2=0.60 has same sign LT as Vijay, so difference appears to be Ackermann - VGL poorly describes the t-dependence of the sigL data - GH followed steps similar to Fpi-1 analysis in dealing with this, a significant model dependence uncertainty will have be assigned to the Fpi extraction as a result - these preliminary results do not yet have: - CoinBlocking corr - pion absorption corr - *NB* Vijay also has to check aerogel tray cut in SIMC - Junaid: the data cuts might be buried in the replay script Next Meeting ------------ New 2-meeting/week structure - Thurs: Oct 30 @ 16:00 Eastern/14:00 Regina - PionLT will go first - Fri: Oct 31 @ 11:00 Eastern/9:00 Regina - we will continue where we left off