May 7-8/26 PionLT/KaonLT Analysis Meeting Notes ----------------------------------------------- (Notes by GH) Today: KaonLT will be discussed first Thursday: Present ----------------- Regina - Garth Huber, Nathan Heinrich, Alicia Postuma, Dex Yadlowski, Nacer Hamdi, Nermin Sadoun, Muhammad Junaid, Vijay Kumar FIU - Pete Markowitz Virginia - Richard Trotta JLab - Dave Gaskell CUA - Chi Kin tam, Tanja Horn, Sameer Jain Glasgow - Kathleen Ramage, Rachel Montgomery Richard ------- KaonLT Q2=4.4 W=2.74 LT-sep analysis - refining the empirical fit used underneath the Lambda MM peak - shape is a Chebyshev order 2 polynomial - changed the MM range where the fit is applied - *NB* still need to compare data to SIMC (tail matching) to be sure radiative tail is not over subtracted - added various checks in the background fit: - mostly based on the the Data/MC Ratios, e.g. #t-phi bins that have Data/MC ratio > 3 sigma from unity - also a kinematic fit score: compare data to SIMC shape for different variables - Garth: the kinematic score makes sense, but the first 3 criteria are based on the SIMC model, concerned that this will amplify the model dependence. Is there a less model-dependent way of implementing a "smoothness" criterion, to make sure the amount of subtracted background does not vary suddenly between 2 bins? - Nacer: what about trying Gabi's background subtraction method, i.e. implementing a Q-factor? - Richard: would need more clarification from Gabi on it before implementing - Garth: will you use the variations from this study to determine also the background subtraction systematic uncertainty at the same time? - *NB* Yes, that is the plan. Will also cross check results w/ Chi Kin - did a background fit study with #t-bins varied from 2 to 4, and #phi-bins from 8 to 10, to see which binning gave most reliable results according to the above criteria - Nacer: his worry is that you try to get Data/MC ratios near 1 by varying the background, instead of optimizing the Lambda MM peak fit region - Richard: not yet comparing background subtracted MM to SIMC, will need to modify the code to do that - each binning is scored according to different metrics, with weighting to obtain a composite score: - kinematic fit: 15% - 3 Data/MC ratio criteria: 20-35% each, totaling to 80% - #valid Data/MC ratio bins: 5% - Garth: how was this weighting determined? - Just by intuition - *NB* Garth suggests to increase the kinematic fit score to 50%, to reduce model dependence, and more closely tie the subtraction to the data - Dave: what is the physical origin of the background you are trying to eliminate? The origin should inform the strategy used to remove it - points out worse PID for high epsilon data, due to lack of RFtime cut - ending up with nearly zero bkd subtraction at low epsilon after the improved HGC hole cuts - high epsilon studies with these criteria are still running - Tanja: how didyou validate the background subtraction? - the above criteria vs background scale factor Chi Kin ------- KaonLT Heep offset optimization - spoke w/ Dave and confirmed the phi offset is applied incorrectly in hcana - both offsets need to be applied: hphi_offset+h.oopcentral_offset - *NB* will make modifications to hcana and push changes - Dave also said oopcentral offset needs to be applied in SIMC input file - this will affect exactly where events are generated - *NB* needs to confirm w/ Dave on correct way to do this - htheta_offset, hdelta_delta offset were set to zero in the SIMC input files he found - *NB* Garth: please send me the Heep information from your new analysis, so he can recalculate the HeepCheck offsets for comparison to yours Alicia ------ KaonLT u-channel PID cut corrections - using PID cuts for protons: Aerogel < 4npe RFtime HGC < 2npe + hole-cut - Aerogel "Efficiency": caused by knock-on electrons from protons in Aerogel - Garth suggests to call a knock-on correction instead of an Efficiency to avoid confusion - RFTime "Efficiency": Junaid corrects for valid events from tails of RFtime peak that are removed by the timing window cut - For Aerogel Efficiency following the method from Bill's Thesis Sec 5.3.8 - used HeepCoin events for clean proton sample - applied PID, acceptance, CoinTime, Missing Energy Cuts - Bill obtained 92.7 +/- 1.6% efficiency, applied as a global factor to omega data - redoing that study here - is the result rate dependent? - Plot vs SHMS-3/4 rate from 2.2-2.9 kHz - no clear dependence, but HeepCoin data cover a narrower range of rates than physics data - sees a beam energy dependence (proxy for SHMS momentum dependence): 93.5% (6.2 GeV) to 90.1% (10.6 GeV) *NB* Garth: it would be worthwhile to get Nacer's HeepCoin data, to get a wider SHMS momentum range - it appears one could get a point as low as 2.5 GeV/c SHMS momentum - Nacer: the 10.6 GeV Heep CoinTime peak seems very broad, the 8.2 GeV peak is much narrower - Does Alicia's Geant4 proton loss code simulate the effect of knock-on electrons? - shmsPA counts Cherenkov photons, not NPE - seems that the Geant4 code cannot be used to calculate this. On the other hand, it also means the number from the code will not double-correct for this effect - can try to use the Physics Data to determine this effect, and compare to Heep result - Garth: not sure the physics data are sufficiently clean to reliably do this Friday: Present --------------- Regina - Garth Huber, Nathan Heinrich, Alicia Postuma, Dex Yadlowski, Nacer Hamdi, Nermin Sadoun York - Stephen Kay CUA - Chi Kin Tam, Sameer Jain, Tanja Horn Glasgow - Kathleen Ramage JMU - Gabriel Niculescu Virginia - Richard Trotta JLab - Dave Gaskell Nacer ----- KaonLT Low Q^2 LT-sep analysis - replay with CoinBlocking correction is completed, now included in Qeff calculation - had to resubmit jobs due to SciComp issues - observes no big changes after CoinTime blocking corr added - doing more iterations - plans to show separated cross sections next week, then on to systematic uncertainty studies Nathan ------ PionLT Q2=5.0 W=2.95 LT-sep analysis - preliminary diamond plots shown, will need to make adjustments to 2 corners - t-resolution plots (SIMC t-recon vs ti) looks very bad - looked good straight from SIMC, before recon_hcana - *NB* Gabriel: it is likely a -t vs +t issue, in SIMC ti is actually -t, in recon_hcana t is +t, so need to add instead of subtract t-recon from ti to get the t-resolution Sameer ------ PionLT Q2=1.6 LT-sep analysis - ran first few scripts in Junaid's framework, essentially following same steps as Nathan - need to draw diamond - only replayed SHMS_center setting so far, need to run others before looking at t-binning, etc Nermin ------ PionLT Lumi analysis to determine LD2 boiling correction - 9.2GeV beam Lumi set #1 Carbon - showed Relative Yield vs Current and vs ELREAL_rate - TLT plots: Red=EDTM Blue=CPULT*ELLT where ELLT is calculated from combinatoric equation - Runs 12143-12154: HMS: scaler, NoTrack, Track yields look flat SHMS: get some slope - we compared to Nathan's result, they look similar - Nathan: Scaler Yield boiling slope indicates some small error in ELLT NoTrack Yield exhibits anti-boiling, indicating an error in CPULT in the opposite direction Track Yield has same anti-boiling effect, indicating that TrackEff is probably okay (i.e. the anti-boiling was not worse) - Dave: ELCLEAN would be cleaner than ELREAL, but recalls that Nathan tried this and it did not help - Nathan: maybe its an issue with just this setting, suggests to look at other settings to see if the problem persists - 9.2GeV Lumi set #2 - plots look similar - comparison to Nathan's analysis indicates he had same issues - 6.4 GeV Lumi Carbon Runs 16738-46 - HMS: slope is a bit bigger than Nathan's - suggestion is to look again at PID cuts - SHMS: will try to make the slope for this a bit better too - 6.4 GeV LD2 Lumi scan - point at 80uA is a bit low compared to trend - Nathan thinks there are likely ELLT issues for >200kHz rate - 9.2 GeV LD2 Lumi #1 - CPULT looks weird vs rate, jumps around a lot, non-monotonic - Nathan: this needs more investigation - particularly please check if the 45uA run has something wrong, such as an error with ELLT calculation - Dave: which BCM is being used in this study? - Nathan: it is supposed to be BCM2, with the non-linearity correction turned on - *NB* Nathan: please recheck the current cuts used in this study, it could be that they are either too loose or incorrect - this is the first time these runs have been replayed, so that seems a likely issue - Gabriel: based on the scatter or slope of the Carbon data, we can evaluate a systematic uncertainty that we apply to the LD2 Lumi study - 9.2 GeV LD2 Lumi #2 - HMS shows anti-boiling - *NB* Nathan: suggests to look first at Current Cuts before the PID cuts Kathleen -------- PionLT LD2 analysis - will start soon on Lumi study - Rachel and Kathleen discussed, will recheck Nermin's result and then analyze the scan at 7.9 GeV Next Meetings ------------- - Thurs: May 14 @ 13:00 Eastern/11:00 Regina - PionLT will go first - Fri: May 15 @ 12:00 Eastern/10:00 Regina - we will continue where we left off *NOTE THE NEW TIMES AND ZOOM INFO*