Mar 5-6/26 PionLT/KaonLT Analysis Meeting Notes ----------------------------------------------- (Notes by GH) Today: PionLT will be discussed first Thursday: Present ----------------- Regina - Garth Huber, Nacer Hamdi, Muhammad Junaid, Alicia Postuma, Nathan Heinrich, Nermin Sadoun CUA - Chi Kin Tam, Sameer Jain Virginia - Richard Trotta Ohio - Julie Roche FIU - Pete Markowitz CSULA - Konrad Aniol Junaid ------ Q2=3.85 W=2.62 LT-sep - added another t-bin at higher -t, divided last bin into 2 - now have 7 t-bins - sigL follows a fairly monotonic trend (minus fluctuations), dropping with -t - Data/MC ratios have some oscillations for last 3 t-bins at low epsilon, high epsilon ratios are more consistently near unity - met with Sameer for 2 hrs this week on LT-sep code - comparing physics yields w/ Nathan, using same SIMC parameters and the new 7 t-bins Next steps: - will evaluate systematic uncertainties, which will vary with t-bin Nermin ------ PionLT LD- PID studies - new NGC calibration using 15 runs from 12027-46 - shows Poisson fits for PMTs 1-4 - gain factors are a bit different than last week (only 3 runs), the difference is up to ~20%, depending on PMT - Discussion: should the gain factor vary run-by-run? - need to calculate the error bar on the gain parameters - do a study of gain params vs run number - if the gains are reasonably consistent within uncertainties, then it is good to combine them to get an overall gain factor with smaller uncertainty - if there is a sudden change in a gain param, some running condition changed and can only combine runs before and after the shift - replayed data w/ new NGC calibration - use of the NGC for e-/pi- rejection is not looking optimistic Nathan ------ - was ill much of the week, did some data analysis comparisons w/ Junaid Sameer ------ KaonLT CoinTime Blocking studies - studies completed for Q2=2.115 to 5.0 - working on Q2=0.50 now - waiting on new data replay from Nacer (with extra ROOT branches) - should have results next week - asks about lack of labeled CoinLumi runs in KaonLT - this was something we did only for the first time in PionLT - KaonLT took various physics data were the beam current was intentionally varied by a factor of 2-3x, these runs can be used - *NB* Richard will give Sameer the run numbers for these studies - Sameer can then apply his CoinTime Blocking correction to the yields to see if the dependence is flat - Junaid: it would be useful to put the CoinTime Blocking factor into the hcana Report Files - Nathan will send Sameer a template example - Richard would like to include this in his next replay, so it needs to be completed soon - *NB* Richard will instruct Sameer on how to post slides on RedMine, apparently his account is not yet added to the RedMine group Nacer ----- KaonLT Q2=0.5 model optimizations (K+Lambda) - last week, Richard noticed that sigT looked like a pole term, while sigL did not - tried reversing them, sigL now pole-like, sigT not pole-like - did some iterations, confirmed the fit params are different - differences in separated cross sections are tiny, can only see the difference when looking at the numbers, plots are barely different i.e. model dependence is small, which would be good news - Data/MC ratios are a bit better with sigT pole-like, so will retain that version - turned MM-shift on/off and investigated effect on separated cross sections - did 1 iteration - sigT varies ~5% - sigL varies ~10% in lowest t-bin, large t-bins have similar effect in magnitude, but a larger fractional effect (>100%) due to very small cross section - Garth: it is good news that sigL at low -t is only affected 10%, but this is likely an over-estimate of the systematic error - *NB* rather than MM-shift on/off, try applying the t-shift calculated by GH from MM-shift - preparing ROOT files for Sameer's CoinTime Blocking correction - asked about the difference between Autumn18 and Winter18 RefCut files - Nathan: need to produce ROOT files with the correct branches, to confirm the cuts on RawCoinTime are appropriate - *NB* Nathan will give Nacer plotting scripts for RawCoinTime plots w/o overflows at 10^38 Garth ----- Shift in t implied by MM peak shift correction - modified his relativistic kinematics program to do this calculation - MMshift = difference between correct and expt values MMexpt=MMcorrect+MMshift (i.e. opposite sign of the MMshift applied to data) - keeping Q2, W, and meson CM-angle constant, then calculate the change in meson kinematics implied by the MMshift - meson momentum and meson lab angle changed slightly - then calculate t tEXP=tCORRECT+tSHIFT (i.e. apply the opposite sign of tSHIFT to data) - GH supplied tSHIFT values for Chi Kin, Nacer, Junaid MMshifts - Chi Kin: can the shift be applied on event-by-event basis? - No, one calculation per SHMS setting, not per t-bin - agrees that this is slightly inaccurate, as the true shift will vary with t-bin, but the dependence appears to be small - *NB* GH will post a cleaned up version of the Fortran code Friday: Present --------------- Regina - Garth Huber, Alicia Postuma, Muhammad Junaid, Nacer Hamdi, Nermin Sadoun FIU - Pete Markowitz York - Stephen Kay Virginia - Richard Trotta CUA - Chi Kin Tam JLab - Dave Gaskell JMU - Gabriel Niculescu Glasgow - Kathleen Ramage, Rachel Montgomery Alicia ------ u-channel proton PID studies, Q2=3.0 W=3.14 centerSHMS high epsilon - applying HGC, Aerogel, RF cuts (when available) - MM cut is not applied until after shape study in physics analysis - shows some preliminary efficiencies per detector - HGC has a hole cut - *NB* Garth: need to treat the hole cut like an acceptance cut, it should be applied in both numerator and denominator in efficiency calc - the reason why it must be included in denominator is that the inefficiency is not uniform, and scaling up the efficient regions to account for the inefficient region will produce a new error - Aerogel eff is 79%, which is suspicously low - Discussion: accuracy of proton efficiencies in report file? - *NB* Junaid suggests the PID cuts used should be rechecked - Dave: a