Feb 6/25 PionLT/KaonLT Analysis Meeting Notes --------------------------------------------- (Notes by GH) Today: PionLT will be discussed first Present ------- Regina - Garth Huber, Alicia Postuma, Muhammad Junaid, Ali Usman, Nacer Hamdi, Vijay Kumar, Nathan Heinrich CSULA - Konrad Aniol FIU - Pete Markowitz Virginia - Richard Trotta CUA - Tanja Horn JLab - Dave Gaskell Short discussion on status of High Q^2 p(e,e'K+)Sigma0 analysis - Richard and Tanja had a discussion - There are 2 main parts to this analysis a) Sigma0 L/T-separated cross sections (where statistics allow) b) g_pKLambda and g_pKSigma coupling constant comparison - Richard would appreciate Gabi and Ioana's help on the cross section analaysis - GH will put Gabi and Ioana in contact with Richard Junaid ------ PionLT data analysis - HMS magnetic optics - currently using phi offsets=0 for both spectrometers - looked at some old files (Stephen's online analysis) and found non-zero offsets, SHMS: -8E-4 rad, HMS: 4.9E-3 rad - Richard: we discussed this before See Nov 21/24 meeting notes at: https://redmine.jlab.org/attachments/2673 - agreement that the offsets are set during the ME fitting and should not change - Dave: low momentum HMS ME should come from 6 GeV era - Ali: thought Holly made a newer set of low momentum HMS ME in the 2017 commissioning period - Tanja: take a look at https://hallcweb.jlab.org/wiki/index.php?title=12_GeV_HMS_Optics_Data this page lists ME only for >5 GeV/c from the commissioning period, nothing listed for low momentum region which must come from 6 GeV - for higher energy ME, using NPS offsets, for lower energy using zero offset - Dave: *NB* will check, has seen various offset values floating around - implemented NPS ME for 5.8, 6.1, 6.7 GeV/c, work still in progress for 5.6 GeV/c Next steps: - setting up for Pass 2 Physics replay - implemented Nathan's boiling correction to Qeff script Nathan ------ - no report, please send comments on WNPPC slides by email Richard ------- KaonLT Q2=4.4, W=2.74 analysis - adjusted and simplified parameterization sigT=p5*exp(-|p6 t|)*QdepT where QdepT=exp*(-Q^4)/Q^2 sigTT=(p13*QdepTT)*ft*sin^2(theta) where QdepTT=Q^2*exp(-Q^2) both use Wfac=1/(W^2-m^2)^2 - putting absolute values in the exponentials helped keep things well behaved - obtain nice agreement in focal plane and physics distribution shapes between data and MC - the only issue is that the ratios are 0.2-0.4 - will have to adjust Wfac, we know from Q2=3.0 analysis that this made a big difference in the Data/MC ratios Alicia ------ Geant4 proton absorption correction - gave an overview of the PA classes defined - added an option to turn/off NGC in detectors.dat - SHMS exit window is moved forward when NGC not in place - only the most dense aerogel is implemented so far - target and SHMS entrance windows are included - had to add Cherenkov NPE to custom stepping action class - event generation: - printed out focal plane variables for a data run into a txt file and reads into Geant4, so actual focal plane distribution is simulated - events are generated at center of LH2 target, where for the target variables Xtar=xfp + xpfp*Ztar Ytar=yfp + ypfp*Ztar - S1X, S1Y, S2X, S2Y energy spectra are generated - energy deposit is >1 MeV, shape looks reasonable - applies an energy threshold per plane based on this distribution, to mimic the effect of the discriminator in the trigger - very preliminary result: 6.4% proton absorption for 5 GeV/c - tried 1-10 GeV/c, get similar absorption for all proton momenta - Ali points out this is consistent with statement in John Matter's thesis - starting to try different particle types - Pete: you will have to turn off pi/K decay in Geant4, since SIMC already takes the decay into account and we don't want to double correct for this - i.e. we want missing triggers due to absorption, not decay - list is made of where different particles stop - can do a cross check between absorption fraction of total in spreadsheet - aerogel tray is about 15% of total absorption - *NB* indicates a need to do different calculations for different aerogel densities - NGC is about 20% of total, which imples a proton absorption correction for KaonLT closer to 5% - Geant4 outputs the nuclear interaction length lambdaL per material - Geant4 numbers a bit lower than PDG except for LH2 - presumably this difference is due to different temperature/pressure than Hall C cryotarget - Garth: *NB* suggests to cross check LH2 density with what is in SIMC input file - some detector configuration checks that were done: - detector positions pulled from SHMS focal plane blueprint - had to convert NGC gas from CO2 to 70% Ar/30% Ne in spreadsheet - *NB* need to check what type of material is used for NGC exit window - HGC gas changed from CO2 to C4F10 in spreadsheet - *NB* Vijay will get Alicia the exact gas pressure used during KaonLT - arranged with Stephen to present at Quarterly Analysis Meeting - everything looks very nice! Thanks Alicia for working on this Nacer ----- KaonLT 3.8 GeV data analysis - fixed problem with SIMC normalization, MC much closer to data now, applied an ad-hoc normalization factor to more easily compare distribution shapes - Lambda data 2x higher than model - Sigma data 9x higher than model - focal plane and physics distribution comparison looks good - now applying a MM cut to select Lambda region - also did a Sigma window and compared Data to MC - Ali: is the MC smearing factor applied? - confirmed mc_shms_hut.f resmult=3.5 so the factor is IN Next steps: - more checks to confirm cuts are OK on some representative files before submitting full data job - will check RF cut and RF cut efficiencies - should add Nathan's LH2 target boiling factor to Qeff - should also add Nathan's ELLT calculation and compare to EDTM to confirm reliability of EDTM before proceeding - Nathan: here is the raw python code, let me know if it is not clear: #calculate the ELLT via individual Hodoplane rates per Dave Mack technique #For details see: https://hallcweb.jlab.org/doc-private/ShowDocument?docid=1063 HODOGATEWIDTH = 50/(10**9) #ns - gate width is PionLT SHMS_HodoRate = [0]*NRATEHODO SHMSTrueRate = [0]*NRATEHODO SHMSDT = [0]*NRATEHODO SHMSLT = [0]*NRATEHODO #HMS_HodoRate = [0]*NRATEHODO for iRATE in range(0, NRATEHODO): #iRATE is the number is the hodoscope plane SHMS_HodoRate[iRATE] = SHMS_Hodo_rate_sum[iRATE]/time_sum[bcm_ix] #HMS_HodoRate[iRATE] = HMS_Hodo_rate_sum[iRATE]/time_sum[bcm_ix] SHMSTrueRate[iRATE] = SHMS_HodoRate[iRATE]/(1 - HODOGATEWIDTH*SHMS_HodoRate[iRATE]) #HMSTrueRate[iRATE] = HMS_HodoRate[iRATE]*(1 - HODOGATEWIDTH*HMS_HodoRate[iRATE]) SHMSDT[iRATE] = SHMSTrueRate[iRATE]*HODOGATEWIDTH #HMSDT[iRATE] = HMSTrueRate[iRATE]*HODOGATEWIDTH SHMSLT[iRATE] = 1 - SHMSDT[iRATE] #HMSLT[iRATE] = 1 - HMSDT SHMS3of4ELT = SHMSLT[0]*SHMSLT[1]*SHMSLT[2]*SHMSLT[3] + SHMSDT[0]*SHMSLT[1]*SHMSLT[2]*SHMSLT[3] + SHMSLT[0]*SHMSDT[1]*SHMSLT[2]*SHMSLT[3] + SHMSLT[0]*SHMSLT[1]*SHMSDT[2]*SHMSLT[3] + SHMSLT[0]*SHMSLT[1]*SHMSLT[2]*SHMSDT[3] #HMS3of4ELT = HMSLT[0]*HMSLT[1]*HMSLT[2]*HMSLT[3] + HMSDT[0]*HMSLT[1]*HMSLT[2]*HMSLT[3] + HMSLT[0]*HMSDT[1]*HMSLT[2]*HMSLT[3] + HMSLT[0]*HMSLT[1]*HMSDT[2]*HMSLT[3] + HMSLT[0]*HMSLT[1]*HMSLT[2]*HMSDT[3] P_S1X_scaler = s_tree["P.S1X.scaler"].array() P_S1Y_scaler = s_tree["P.S1Y.scaler"].array() P_S2X_scaler = s_tree["P.S2X.scaler"].array() P_S2Y_scaler = s_tree["P.S2Y.scaler"].array() #H_S1X_scaler = s_tree["H.S1X.scaler"].array() #H_S1Y_scaler = s_tree["H.S1Y.scaler"].array() #H_S2X_scaler = s_tree["H.S2X.scaler"].array() #H_S2Y_scaler = s_tree["H.S2Y.scaler"].array() Next Meeting ------------- - Thur Feb 13 @ 15:30 Eastern/14:30 Regina - KaonLT will go first - Nathan and Alicia will be at WNPPC in Banff then, please remember to send your comments on their slides by email