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Kaon LT Meetings » mtg_24jun27.txt

Garth Huber, 06/28/2024 12:10 PM

 
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                 Jun 27/24 PionLT/KaonLT Analysis Meeting Notes
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                 ----------------------------------------------
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                                (Notes by GH)
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                     Today: PionLT will be discussed first
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Please remember to post your slides at:
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https://redmine.jlab.org/projects/kltexp/wiki/Kaon_LT_Meetings
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Present
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-------
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Regina - Muhammad Junaid, Ali Usman, Alicia Postuma, Nathan Heinrich,
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   Vijay Kumar, Zach Sullivan, Garth Huber
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JLab - Dave Gaskell
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Ohio - Julie Roche
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York - Stephen Kay
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CUA - Tanja Horn
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FIU - Pete Markowitz
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UVA - Richard Trotta
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Junaid
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------
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PionLT Offsets
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- tested OOP offsets w/ opposite sign and rechecked Heep distributions, got
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  worse for all energies
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- all offset signs now finalized
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- comparison of Data & MC distributions with offsets applied
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  - delta, xptar, yptar, etc. for both spectrometers
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  - overlap of distribution shapes looks pretty good
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- preliminary Heep Coin Data/MC yield ratios
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  - EffCharge = Tracking, DetEff, Hodo-3/4, EDTM corrections applied,
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    LH2 boiling corr from Richard's analysis (8%/100uA, so ~4% correction)
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  - *NB* some inconsistencies in MC to Data normalization seen from
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    plot-to-plot, so plotting scripts need to be re-checked
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  - *NB* need to check that W-cut is applied consistently to both Data and MC
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Next steps:
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- planning to do Pass-2 replays
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  - data were not replayed yet w/offsets, also need to include new BCM calibs
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Nathan & Zach
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-------------
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PionLT Lumi Studies
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- applied uncertainty in current based on BCM calib in terms of unc in slope
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  and offset
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  - *NB* still need to talk to Dave Mack re errors from BCM saturation, will
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    look through DocDB if don't hear from DM within a week
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- Rel Yield vs Current/Rate w/ BCM errors applied
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  - Carbon runs 16727-16737
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  - scaler yields have larger (more reasonable) errors now
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  - *NB* BCM offset clearly needs some optimation, but things generally flat
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- preliminary LH2 boiling study
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  - LH2 seees about 4% boiling @ 80uA
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  - will combine settings for a combined fit
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  - *NB* Procedure to combine settings (from GH):
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    - First do a fit of each setting study and normalize to unity at zero
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      rate/current
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    - Then overlay all of the normalized studies, and check for consistency
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    - If consistent within errors, do a combined fit
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Next steps:
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- look at some 2021 Lumi studies, w/ PreScale correction
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- Look at Coin Lumi settings
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Richard
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-------
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KaonLT LTsep fitting
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- Q2=5.5, Center Setting only, MMk cut and pion subtraction applied
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- fitting sigL=(p1+p2*log(Q2))exp(p3*|t|) and sigT=(p4*|t|/Q2-1)*exp(p6*|t|)
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- result of 1st iteration: Data/MC ratio ~0.7 @ -t=0.465, ~0.5 @ 0.590
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- did 31 iterations, but ratios did not change, something wrong
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  - GH: *NB* it's really important that the fit for new model parameters
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    converges, otherwise you can't consider it as an iteration
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    - this appears to be the reason why the ratios did not improve
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- meeting coming up w/ Vijay, Ali to discuss proton absorption correction, and
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  rad on/off systematic studies
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Alicia
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------
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Overview of latest updates to BSA paper after comments from this group
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- got rid of 2 planes figure to save some space
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- for the Q2-xB plot, can move symbol legend from caption to inside the figure
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  to save some space
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  - *NB* GH can do this after he gets home
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- will circulate the manuscript to all co-authors later today
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  - comments will be due July 16, the day after Alicia's presentation at Hall
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    A/C workshop
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Ali
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---
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HMS Cherenkov efficiencies
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- to recall, the KaonLT efficiency (~97%) is noticeably lower than in PionLT,
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  what is the reason for this?
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- looked up HMS Cherenkov efficiency study in Bircu's thesis, p.115
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  - plotted CerEff and pion Rejection Factor for different NPE cut
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  - had a similar Efficiency to Ali's KaonLT study, ~2-3% inefficiency
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- Looked up hclog where the light leak was fixed:
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  https://logbooks.jlab.org/entry/3854383
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  Oct 7/2020 entry by Chuck Mahlong
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- believe the light leak started when broken mirror was fixed in early 2018,
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  before KaonLT started
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  - this means all of KaonLT and summer 2019 PionLT data have the light leak
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    inefficiency
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- conclusion: we understand the reason why the KaonLT and PionLT inefficiencies
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  are so much different and hence can assign a smaller systematic uncertainty
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Vijay
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-----
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Summer 2019 PionLT systematic uncertainty studies
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- added variations in LT, TT for RadCor on/off and MM cuts to spreadsheet
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- *NB* LT, TT got larger for RadCor on/off, so we have to consider whether to
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  assign a 1-sided uncertainty, similar to what Alicia needed to do for BSA
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- relative uncertainties show, better would be to tabulate the absolute
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  uncertainties per t-bin
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Next steps:
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- looking at acceptance cut systematic uncertainty
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  - applying +/-10% cut variation, same as in Tanja's thesis
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 Next Meeting
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-------------
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* NOTE* we do not meet next week due to July 1 (Canada) and July 4 (USA)
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  holidays
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- Next meet: Thur July 11 @ 15:00 Eastern/13:00 Regina
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  - KaonLT will go first
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