Aug 22/24 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, Ali Usman, Alicia Postuma, Muhammad Junaid, Nathan Heinrich, Vijay Kumar, Nacer Hamdi Virginia - Richard Trotta JLab - Dave Gaskell Ohio - Julie Roche CSULA - Konrad Aniol Richard ------- KaonLT Q2=3.0, W=2.32 setting - HMS-delta shows lots of discrepancies between Data and MC distributions, they peak in different spots and have markedly different shapes - HMS-delta vs XPtar, unweighted MC dist fills the same phasespace as the data, but distribution is much different - the fact that the filled phasespace has the same shape is good news, so it's a weighting issue, not something more fundamental - the MC functional form must be completely inappropriate for these kinematics - SHMS-delta vs XPtar, data have a weird banana region at delta~0 that is not shown in the MC - data are not pion subtracted, so maybe it's a pi+ leakage issue? - *NB* it's important to be sure the data dists are clean from pi+ leakage when making comparo to MC. Next time, please also show a MM plot of the data used for the distributions, so we can see how much contamination there is. Nacer ----- KaonLT Heep Studies - concentrate on 8.2GeV data, where Exp/MC=1.12 - MM dist shows a small bump at pi0 threshold that needs to be removed - it would be best if this could be removed with some cut with less cut-dependence than MM, but that might not be possible - Ali: *NB* select just the pi0 events with a MM cut and see where they end up in the other distributions - the Heep MM distribution is much narrower in MC than Data - *NB* need to use Ali's resolution tuning result in the MC, so that the MM distribution gets closer to the data - probably will eventually need to use a MM>0.10 cut, so it will be important that the MC more closely resembles the data, to reduce the cut dependence - *NB* a MM cut dependence study would be required as well - closer look at the Exp Yield ingredients for this setting - two notable low effs are EDTM_LT ~89.5% and SHMS_Hodo-3/4 ~97.3% - concentrate on the EDTM for now - extracts ElecLT from two methods: 1) ElecLT=EDTM/CPULT 2) calculated from 55ns Hodoscope discriminator width - method 1: Run 7974 ElecLT=95.6%, 7975=99.4%, 7976=99.6% - method 2: some discussion on how to correctly calculate this - need the total trigger rate from both arms HMS: ELREAL rate SHMS: 3/4-trigger rate The total of these two is about 4kHz - Dave: the Hodoscope discriminator width should always be 55ns, so Method 2 should work the same way for all beam periods, even when the trigger timing changes - Dave: *NB* please compare the beam current for these 3 runs and the %time that the beam current is over threshold, so we can better understand the variation between run 7974 and the others - plots shown of HMS-delta and SHMS-delta vs MM - the Heep data distribution has a blob on one end while the MC distribution is more uniform - this blob can't be due to pi0 contamination, since it occurs at elastic MM - *NB* also need to investigate use of different HMS-Matrix Element for intermediate momenta, as suggested last week - *NB* setting up an offline meeting on this w/ Dave would be a good idea Junaid ------ PionLT Heep study - 2022 data had a broader EM distribution than others - fixed raster correction, dists now sharper, more similar to 2021 data - extracted new mean values and gave to GH for Offset Fitting - looking at efficiencies to better understand non-unity Exp/MC ratios - SHMS_Hodo-3/4 effis are low ~89% - Plane-by-Plane efficiencies show a decreasing efficiency with plane number - Plane 4 (the quartz bars) has an eff of only ~61% - *NB* suggest to look at efficiencies vs rate, if it is real there will be correlation, if it is something else, it will be more random - also looking at pi0 contamination study, given Nacer's findings Ali, Alicia, Vijay ------------------ - no reports - congratulations to Vijay on the successful PhD defense! Future Meetings --------------- - the current time will not be good for both Julie and Nacer due to conflict with teaching - Julie will be available at 4pm and 11am Eastern - GH will set up a poll to find a new time, starting in September Next Meeting ------------- - Thur Aug 29 @ 15:00 Eastern/13:00 Regina - PionLT will go first