Dec 7/22 PionLT/KaonLT Analysis Meeting Notes --------------------------------------------- (Notes by GH and SJDK) 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, Stephen Kay, Ali Usman, Alicia Postuma, Nathan Heinrich CSULA - Konrad Aniol, Erika Gwin CUA - Richard Trotta JLab - Dave Gaskell Ohio - Julie Roche, Jacob Murphy FIU - Pete Markowitz Richard Updates --------------- - LT separation code - it's slow getting information back from Bill - Heep analysis - SIMC/hcana calculate variables differently - Adding new variables that calculate it in the same way as hcana into SIMC - DG - In complete recon event or a new subroutine? - In a new one - DG - Should be fine - Maybe call it "recon_hcana"? - Don't do it as a separate branch! - Will be annoying to integrate, also everyone will want this - New submodule is good, will be modular then - Total Efficiencies per run for each setting - Needed input into Bill's LT-sep code - Haven't incorporated Ali's updated efficiencies - Error bars are off as a consequence - Some are grabbing the wrong calculations too - -t binning plots/demonstrations shown for Runs 4965-5009 Left-Cent-Right - ~2% downtrend seen in Effs for Right setting, probably following real changes in running conditions - Actual t-binning and diamond cuts will be done in Bill's LT-sep code - Need to use Jacob's code to apply diamond cuts - GH - For MMK plot, should zoom in on Lambda peak and see if it's stable versus run number. Apply finer binning too - RT - Will add it, will do 2D phi dist too - GH - also need to add a slide of what Effs and typical values are used in the TotEff calc, so we can see exactly what was done - *Need to do a HMS calorimeter efficiency study*, can't rely on what the report file gives - DG: this needs to be for all PID detectors - need to select some runs which are sufficiently clean and then apply the obtained values globally, preferably vs. spectrometer momentum - often, can never get rid of enough pi- (for HMS), so might even have to resport to Heep data, but then have to worry about not illuminating the full focal plane - the studies are simple, but this needs to be completed before starting LT-separations - iFarm issues - Tape silo had a robotics failure yesterday, can't get stuff from the tape silo currently - can only replay data already cached to disk Ali Updates ----------- - Updates to Error Calculations - Heep coin data from 6.2/8.2/10.6 GeV - Error bars were too big - New calculation using binomial errors - need to *add* a slide showing old and new calculations - New calculation shrinks error bars quite drastically - For 8.2 Gev, maybe even too small - 10.6 GeV looks good with one outlier - All efficiencies seem to be lower for this point - Has lowest beam on time? - DG - Need to *correct* EDTM LT for time the beam is off - the issue is that the EDTM keeps counting when beam off, need to correct the scalers via an approximate formula derived by PBosted - Richard's Lumi script should do this? - DG - *Current off correction* from PBosted study: - LiveTime=(Rmeas-(1-f))/f - Rmeas = edtm_accepted/edtm(nominal edtm live time) - f = current(no cut)/current(with threshold) - this formula is an *approximation*, assumes the beam ramp up time is negligible, which may or may not be true, depending on the running conditions, probably this approximation will be worse for early 10.6 GeV running - AU - probably tnis is NOT implemented yet for Heep, physics settings, will discuss with RT - Delta-Pi - Ali has received an invitation from Stefan Diehl to present some Delta-Pi results at a conference at ECT* in Trento in August - will discuss JLab conference travel funds application with RT Stephen Updates --------------- - No new progress on RF class - Will update hcana in group directory to use new RFtime variables - Stephen will try to do this today, let him know if there are any issues with the new hcana version, should only affect the CT/RF classes - Should not need a DEF file change - RFTime.* is in there currently, this will pick up new variables Alicia Updates -------------- - BSA analysis - Edited report files to calculate effs separately for each helicity - Can't separate charge by helicity - Will cut charge in half to normalise dummy subtraction - DG - Should contact Steve Wood wrt to helicity scalers - Might've been added for A1n/d2n? - SK - Would explain why helicity scalers didn't work for KaonLT but were added later (but still had issues) - AP Should CC Carlos Yero when asking Steve on this - shown runs have same TotEffs for +,- helicity to 3rd decimal point but LH2, Dummy do have a different Effs - DG - HGC pion efficiencies are way too low - Just set them to 1 until RT/AU complete their study - Weighted average of BSA for Left-Cent-Right - Experimented w/Complete fit (A=sin-phi,B=cos-phi,C=cos-2phi) and Approximated fit (A=sin-phi only) - complete fit is over-fitting the data, ending up with B,C>A for some fits - DG - can constrain B,C based on world data - we have LT,TT from Fpi-2 but only up to Q2=2.45 - also have CLAS data - SK - Glancing back at old code from his PhD analysis @ Mainz: he ran an *initial fit* with just one Sin/Cos term (dashed red for Alicia), and then fed this into the second fit - Can adjust the second fit in a few ways then, can constraint the asymmetry A to vary in some range, such as permitting A to only vary within 1-2sigma of initial fit - B/C can also be restricted too - Julie discusses some of the difficulties of interpreting the results that were used when presenting DVCS BSA data - Suppressing B,C terms can make things look "more precise", but actually shrinks the error bars in an unrealistic manner - in the end, the DVCS paper presented both sets of results in a paper and gave a caution that the result and obtained error bar depends on how the analysis is done - GH - Could quote weighted everage of complete/approx fits? - DG - What about *radiative corrections* to the BSA? This is an issue that just occurred to me now - GH - Unlike the LT-sep results, we aren't quoting a cross section. Not using SIMC to get asymmetry, while we use SIMC in the ratio method to get the cross sections - DG - Yes, Acceptances should cancel in the BSA - GH - From SIMC studies for LT data, can *estimate* how large radiative corrections are for a t bin by turning on/off the rad-corr in SIMC and and how large the effect is, no easy way to see how this corrects the asymmetry - DG - Iterative fit? Put SSA into SIMC and see how it changes things when RadCorr On/OFF - maybe can also use SIMC to do t-bin centering for BSA, just like we do for the cross sections via the Ratio Method - DG - Interesting question, could be an advantage over CLAS analysis in that we can actually study and estimate the RadCorr effects. Will think about this further Next Meeting ------------ Wed Dec 14 @ 9:00 Eastern/8:00 Regina/6:00 Pacific - PionLT will go first