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Kaon LT Meetings » mtg_22nov09.txt

Garth Huber, 11/10/2022 05:16 PM

 
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                 Nov 9/22 PionLT/KaonLT Analysis Meeting Notes
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                 ---------------------------------------------
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                           (Notes by GH and SJDK)
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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 - Garth Huber, Stephen Kay, Ali Usman, Alicia Postuma, Love Preet,
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   Vijay Kumar, Nathan Heinrich, Muhammad Junaid
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CSULA - Konrad Aniol, Johnathan Conrad
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CUA - Richard Trotta, Tanja Horn
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JLab - Dave Gaskell
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FIU - Pete Markowitz
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SBU - Wenliang (Bill) Li
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Ohio - Jacob Murphy, Julie Roche
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Bill LT Software Tutorial - Recorded
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------------------------------------
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The recording is posted at:
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http://lichen.phys.uregina.ca/~huberg/kaon/LT_tutorial_20221109_1920x1080.mp4
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- LT separation overview
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   - based on c++/ROOT
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   - cross-checked translation of PAW kumac codes used in Fpi-2 analysis
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   - Tanja's kumacs were different than Jochen's (Fpi-1), but separation method was similar
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- 8 phi bins, 3 u (t in our case) bins
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   - the #bins is based on statistics and kinematic coverage, yours will be
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     different!
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   - each (W,Q2) setting is done separately
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   - ubin_interval: specifies ranges of u-bins for each (W,Q2) setting
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- Background subtraction
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   - will be less complex in Pion/Kaon case, fewer simulation inputs needed
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- 10 step flow chart
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   - Efficiency (run by run)
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   - Yield extraction in root_ana folder
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   - Plot combination
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   - BG subtraction (bin-by-bin in Bill's case)
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   - Sum angles
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   - ...
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- Some files in the git repo are archival, should be moved to separate folder
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  when a HallC version of repo is made
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- Richard points out that lots of cuts done in Bill's code are already done in our analysis
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   - Rather than removing cut function, Bill recommends just adding in a "blank"
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     cut that does nothing and applying it to the incoming trees
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- Angles added and dummy target subtracted in the same script
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- scalers_fpi contains scaler text files run-by-run for each setting
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- original analysis structure of Fpi-2 PAW kumacs is retained, so everything is
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  in separate files.  Bill recommends to NOT consolidate files, since
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  everything is working well and follows structure of previously tested code
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   - analysis.cpp is verified translation of kumac code
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   - In analysis.cpp file, just assign cuts to Dummy cuts, since we will have
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     cuts done elsewhere
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- the code setup allows run-by-run efficiencies to be applied in the normalization
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- Existing LT sep code does cuts in a somewhat problematic way
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   - Uses ROOT trim functions to apply cuts
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   - T->Draw("...", "...Cuts...") etc
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      - This is fine for quickly drawing plots, but not ideal for final
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        analysis
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      - it was only done this way because Bill was a grad student, and learning
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        how to do things
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      - now he's more experienced and understands that going forward, this
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        should be changed to an *Event-Based IF loop*
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- Once analysis makes root ana etc, this is the only input for subsequent steps?
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   - Yes, from that point this is all that's needed
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- Bill suggests to first look at Heep code to understand the structure of the code
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   - Bill will move setup examples to somewhere on the farm
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      - Stephen will copy to c-kaonlt or similar
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      - Sample data, sample simulations
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- How are SIMC weights re-calculated?
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   - For each iteration, don't re-run SIMC, just recalculate the weights
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Jacob Updates
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-------------
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Optics:
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- meeting with Holly on Thursday
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  - trying to get improved ME for HMS=5.9, 6.8 GeV/c
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  - rewriting some scripts to make them more user friendly
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- Xsieve resolution is much worse than Ysieve
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   - x resolution for upstream foil isn't great even at -8 - -6.5 in delta
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   - Mark J has seen similar issues
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   - will have more results next week
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- Going through standard.kinematics
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   - 2022 easier, some missing angles from 2021
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   - 1 in 5 settings or so has angle off by ~ 0.01
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   - Should be done by today for 2022, 2021 is already done
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- Need to set up hallc_replay with PionLT param files
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   - Offline branch exists
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     https://github.com/JeffersonLab/hallc_replay_lt/tree/LTSep_Analysis_2022
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   - Should set up DB/Param directories in similar manner to KaonLT
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      - https://github.com/JeffersonLab/hallc_replay_lt/tree/LTSep_Analysis_2022/DBASE/COIN/DB_KaonLT
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      - https://github.com/JeffersonLab/hallc_replay_lt/tree/LTSep_Analysis_2022/DBASE/COIN/DB_PionLT
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      - As an example
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- Determing Pc (central momentum) offsets
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   - Apply FP cuts, electron PID cuts
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      - etottracknorm > 0.8
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      - npeSum > 2
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      - abs(delta)<10
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   - Graphical cut to select elastics along W vs xfp and W vs xpfp
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   - Narrower cut placed to select central momentum region Mark Jones' request
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       - abs(xfp) < 2
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       - abs(delta) < 2
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   - Using FP variables and optical matrix, recalculate W using updated
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     central momentum (set by hand)
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       - choose value that gives best proton mass
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       - offset is difference between Optimized Pc and Set Pc
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   - Jacob outlined procedure and sent to Vijay/Ali
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- Garth Q - SIMC calculation same as hcana calculations, still on the list?
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   - Richard - Yes, looked at but not implemented yet
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Nathan Updates
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--------------
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- Showed draft slides for PhD committee meeting, received many comments
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Junaid Updates
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--------------
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- Working on PhD committee slides
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   - draft not shown
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Vijay Updates
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-------------
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Luminosity scaler study from PionLT (summer 2019)
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   - Carbon lumi data from 2.7 GeV
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   - Using EL_REAL triggers
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   - Both spectrometers behave in similar way, which is good
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   - Dip at low current should be fixable by adjusting the current offset
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- Working on non-tracked and tracked normalized yields next, to see if they
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  behave similarly
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   - Also going to look at BCM offsets
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- Stephen/Garth/Dave:
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   - Can't apply a run-by-run current offset
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   - BCM calibration has large uncertainty at low current <10uA
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   - Offset is applied to ALL runs or NONE of them
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   - It is the SAME BCM so cannot apply different current offset to different
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     runs
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   - There is second effect going on which is giving rise to the positive
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     trend, need to also look at the electronic livetimes
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   - Best to adjust one thing at a time
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   - Get the low current sorted first using the BCM current offset
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      - Should be fixable with a current offset adjustment
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      - This is by far the dominant effect at low current
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   - Then investigate the remaining effect at larger I
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Next Meeting
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------------
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Wed Nov 16 @ 8:15 Eastern/7:15 Regina/5:15 Pacific
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- KaonLT will go first
(115-115/413)