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Kaon LT Meetings » mtg_24sep12.txt

Garth Huber, 09/12/2024 10:44 PM

 
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                 Sept 12/24 PionLT/KaonLT Analysis Meeting Notes
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                 -----------------------------------------------
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                                (Notes by GH)
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                     Today: KaonLT 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, Nathan Heinrich, Alicia Postuma, Vijay Kumar,
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   Nacer Hamdi, Muhammad Junaid, Ali Usman
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Ohio - Julie Roche
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JLab - Dave Gaskell
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Virginia - Richard Trotta
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CUA - Tanja Horn, Casey Morean
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FIU - Pete Markowitz
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Alicia
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------
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pi+ BSA paper Referee comments
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- general interest criterion:
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  - need to modify title (both editor & referee A)
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  - some parts too technical, reword or move definition earlier
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  - Tanja: stress importance of confirming CLAS measurements w/ different
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    systematics
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- improve discussion of theory vs data agreement
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  - Tanja: change from discussion of models, to discussion of the physics
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    represented by the models
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  - *NB* with improved data and models, we can make a more definitive statement
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    than prior works on the approach to the GPD regime
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    - GPD regime not reached yet, as the GPD model does not describe data well
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    - interestingly, there is a non-perturbative model that encapsulates the
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      major features of the data
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- modify figure to make syst uncertainties more clear
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  - Dave: *NB* remove cap on outer error bar
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  - Tanja: if new figure is not an improvement, include it in a note to the
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    referee, so they're aware we tried
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- comment on backgrounds
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  - pion purity - side study using HGC w/hole cut, detector efficiencies
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- overall, fairly optimistic on eventual acceptance
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- expecting a new draft for comment in 1-2 weeks
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Richard
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-------
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KaonLT LT-separations
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- plot of Data/MC ratio per t-phi bin for high, low epsilon data combining all
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  settings
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  - ratios are 0.1-0.5 with some variation
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- will try reproducing Vijay's data using RT's code, hoping to find what the
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  problem is
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  - has run# for center setting from Vijay, replaying data now
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Vijay
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-----
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Next steps for low Q2 pi+ LT-separations
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- setting up SIMC for ALMA9
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- first step is to understand why HMS detection volume cut dependence is so
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  large
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- then Q2=0.42 data
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- Fpi extraction will wait until other studies done (proton absorption,
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  systematics)
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- shows LT-separations from thesis
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  - had changed LT,TT functions from last update
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  - sigLT increased further at lowest t-bin when changing bin
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  - ratios flatter than last update, particularly at low -t
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  - *NB* ratios still have some oscillations for higher -t bins, indicates that
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    t-dependence in LT,TT functions still not right
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Ali
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---
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piDelta BSA analysis
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- shows new MM plots per t-bin, Q2=2.1, W=2.95
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  - plots are for thesis, asking for feedback
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  - Delta shape comparison: (Data-Bkd)=RED,  Delta MC=BLUE
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    - agreement is pretty good in main peak region, but divergence is larger on
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      edges
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    - Red is integrated for BSA, not the Blue
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    - Garth: should make sure integration region is where Red and Blue have
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      good agreement
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      - MM cut values: 1.11-1.40
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      - *NB* need to overlay these on the plots to check this more clearly
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Nacer
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-----
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KaonLT Heep analysis
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- Data/MC ratios too large after applying proton absorption correction
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- updated John Matter's materials table for proton abs calculation
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  - removed NGC
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  - adapt values for actual aerogel thickness
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  - obtain absorption factors:
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    3.8+4.9    n=1.030  7.02%
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    6.2+10.6   n=1.015  6.30%
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    8.2        n=1.011  6.09%
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- review of proton correction method in W.Li's thesis (originally developed by
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  Henk Blok)
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  - plot of MMp @ 3.8 GeV
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    - data and SIMC agree up to 0.02
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    - data tail grows past 0.02, disagreement w/MC degrades
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    - MC tail slope gets steeper past 0.04, while data is more steady
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    - analyzing with tigher MMp<0.02 cut gives 5% lower Data/MC ratio
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    - *NB* Dave: it's important to choose one cut and apply it.  Keep the
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      analysis simple.  Don't apply both EMiss and MM cuts at same time
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  - shows SHMS-beta plot for Heep events & compare to Bill's data
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    - Dave: beta trigger is set up differently now, pretty sure you won't get
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      the tail as in 6 GeV era
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    - Dave: *NB* SHMS-beta distribution looks weird, need to check variable
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      beta-p for corrected variation in TOP across focal plane
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  - tries replicating Bill's proton absorption correction method
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    - get fraction ~95%, so no big change from full factor in J.Matter thesis
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    - Bill did have a tigher MM cut than Nacer
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- next steps
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  - Dave: *NB* suggests to simplify the situation by looking at single arm Heep
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    to see if Data/MC ratio is 1 or not
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    - if Heep singles OK, it indicates the problem is with the proton arm in
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      Coin
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    - if Heep singles NOT OK, problem is with the electron arm or beam
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      normalization
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Junaid
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------
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PionLT Heep analysis
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- Data/MC ratios w/ and w/o MM cut, to eliminate pi0 contamination
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- HMS matrix element check
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  - discovered that param files using "standard" HMS ME for ALL settings, no
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    special ME being used for P_HMS>5.5 GeV/c
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  - tried using KaonLT ME for P_HMS+6.59 for 10.5 GeV data
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    - subtle differences from standard ME, slightly better Data-MC agreement,
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      but nothing dramatic
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  - Dave: a student is working on P_HMS=5.78 GeV/c MC
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  - Julie: will check who is working on ME from NPS data
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  - Tanja: *NB* take a look at the slides at:
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    https://indico.jlab.org/event/866/contributions/14919/subcontributions/289/attachments/11532/17851/Ploen_CollabOpticsCalibNPSJuly2024.pptx
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    - slide 12 gives a useful list of who is working on which ME
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    - P=5.639, Julio Gil Guiterrez & Abhyuday Sharda
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    - P=5.878, Josh/Christine
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    - P=6.117, Josh Crafts
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    - P=6.667, Christine Ploen
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- issues w/ Hodo-3/4 effs
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  - looking at hcana code, tried removing PID cuts, got same number
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  - Dave: *NB* for your preliminary Heep yields, try using a high efficiency
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    for now, we will eventually get the effs high as expected
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    - should be ~99% except for runs w/ low momentum in quartz plane
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  - MJ: *NB* we should be able to fix Heep ratios if we solve problem with 3/4
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    trig effs
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    - Nacer also sees too-low 3/4 effs in KaonLT data, so it seems there's a
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      common cause for both analyses, the Heep singles analysis that Dave
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      suggests will make this more clear
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Nathan
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------
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PionLT luminosity studies
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- preparations to look at 2-arm daq ratios from SIDIS lumi scan
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- modifying analysis sript, not there yet
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Next Meeting
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-------------
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- Thur Sept 19 @ 16:30 Eastern/14:30 Regina
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  - PionLT will go first
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