June 5/25 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 Present ------- Regina - Garth Huber, Nathan Heinrich, Ivan Zhenchuk, Muhammad Junaid, Ali Usman, Nacer Hamdi, Vijay Kumar CSULA - Konrad Aniol Virginia - Richard Trotta JLab - Dave Gaskell JMU - Ioana Niculescu Ohio - Julie Roche York - Stephen Kay FIU - Pete Markowitz CUA - Tanja Horn Ali --- piDelta BSA new rebinned results - 3 t-bins for Q2=3.0, W=3.14 and Q2=2.1 - 2 t-bins for Q2=3.0, W=2.32 - 1 t-bin for Q2=4.4, 5.5 Pete: the A_LU phi distributions look like they have little scatter about the fit sine curve, which implies the error bars are over-estimated, can you plot the difference between the A_LU values and the fit curve, so we can more clearly see the fluctuations? - Dave: an alternate suggestion would be to list the chi-squared/dof for each plot so we can see if it's too good or not Next steps: - will work on systematic uncertainties - MM fit-dependence uncertainty - PID cut dependence uncertainty - beam polarization error (a constant value) - some discussion came up in thesis defense on ways to reduce the fit-dependence uncertainty, Ali will investigate and get back to GH and Dave on it Vijay ----- Low Q2 pion and proton absorption study - increased simulated events to 100k as discussed last week - fluctuation @ 2.3 GeV/c is now gone - tried increasing to 400k events as with SIMC, but G4 crashed after 170k events - Nathan recalls that Alicia is reading in a real event file for the SHMS focal plane vectors, probably that file contains 170k events - made changes to yield scripts, to produce individual yield files for each setting, as Nacer and Junaid does - GH requests a copy of these files when done Richard ------- KaonLT LTsep - m_lambda correction now in eps_n_theta.f - thetacm now 9.77-19.62deg, down from 23-30deg before - the difference is roughly 12deg per bin, with the difference more significant for the smallest t-bin - as a result LT, TT need to be completely refit in LT-separations - sees a t-dependence, now trying functional forms LT=p9*exp(-p10**|t|)*sin(thetacm) TT=p13/(|t|**p14)*sin(thetacm)**2 - hitting the edge of parameter fit limits, need to adjust limits - TT fits: fixed p13 and varying p14 in the t-dependence LT fits: fixed p9 and varying p10 - Garth: suggests to estimate p10,p14 t-dependence parameters by hand and fitting p9,p13 while keeping p10,p14 fixed. After p9,p13 are converged, then fix them and try fitting p10,p14 Nacer ----- - shows CAP Congress slides, lots of suggestions Nathan ------ Looking at two issues - HMS timing weirdness, due to 2 hodoscope bars? - something in CoinTime clearly changed when Reference Time cuts were fixed - trying to look at it using the hodoscope calibration script, but the script is not easily allowing CoinTime to be added to the output ROOT tree - also has some LH2 boiling behavior to investigate - will meet with Dave in person next Tuesday, after all-hands meeting Junaid ------ - shows CAP Congress slides, more suggestions Ivan ---- Q2=0.5 BSA analysis - still waiting on data replay - to recap, Alicia had replayed the Q2=0.5 data with helicity enabled, but somehow Nacer's timing offsets were not properly included - Nacer is now replaying the data with helicity enabled - has Nacer's t-bin limits, will investigate - BSA analysis does not apply diamond cut, so the t-range of the data will be larger than Nacer's, will need to add extra t-bins at bottom and top of t-range - calculating mean Q2,W for each bin, look reasonable - will learn how to run SIMC for Lambda,Sigma peak fitting - will get SIMC input files from Nacer Next Meeting ------------ - next week's meeting is canceled, due to so many people being away at CAP Congress - the following week is Juneteenth holiday in USA, so we will meet at a different time - Fri June 20 @ 11:00 Eastern/9:00 Regina - PionLT will go first