Oct 17/23 PionLT/KaonLT Analysis Meeting Notes
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                            (Notes by GH & AH)

                     Today: KaonLT will be discussed first

Please remember to post your slides at:
https://redmine.jlab.org/projects/kltexp/wiki/Kaon_LT_Meetings

Present
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Regina - Garth Huber, Ali Usman, Muhammad Junaid, Nacer Hamdi, Nathan Heinrich,
   Vijay Kumar, Alicia Postuma
CUA - Casey Morean, Tanja Horn, Richard Trotta
FIU - Pete Markowitz

Richard
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Preparing for LT-sep iterations
- Ratio of Data/MC vs. phi for different t bins for both low/high epsilon looks
  more consistent
  - set interference terms LT,TT to zero
  - sigL had a (t-0.2) type term, removed for now
    - the motivation of the (t-0.2) in the Fpi-2 pi-/pi+ analysis was to give a
      simple proxy for t'
    - the dependence of the Ratios vs t once the iterations start will give
      information on what the data will require as far as t-dependent
      parameterization is concerned

- Short routine to recompute SIMC weights after an iteration, to avoid having
  to re-run SIMC after each iteration
  - Still working to improving weight computation
  - Garth: use a ratio method to compute the weights, to avoid recompute
    Jacobians and other factors needed to go from cross section to weight
    New_Weight=Old_Weight*(New_dsigma/Old_dsigma)
  - Confirm the usage of CM frame variables, before computing the weights
  - will almost certainly need to add variables to SIMC ROOT tree to do the new
    weight calculation efficiently

Vijay
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HeepCoin comparison after Garth's offsets
- offsets used were determined using only 2.7, 3.6, 4.5 GeV data
  - Vijay justified this choice by the fact that this set had P_SHMS offset
    equal to zero, which seems more reasonable for these low spectrometer
    momenta
- Improved W value after applying offsets corrections obtained from Garth

Next Steps
- looking at Heep cross-sections using existing cryotarget boiling corr
- also looking at Lumi correction script for Summer 2019 data

Garth
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More on the HeepCoin offsets
- looked at Vijay's data for other variables: EM, PMX, PMZ, W
- the results seems overall in agreement with predicted quantities
  - EM is worst variable in terms of reconstruction, which is disappointing
  - overall, observed behavior with offsets is slightly worse than predicted
- Low Q^2 data at low -t<0.01 is sensitive to correct offsets

- Still need to investigate for other energies
  - Richard should try GH's offsets determined for 3 highest beam energies

  - GH might ask Vijay to rerun using an alternate set of offsets for
    comparison, GH needs to do more study first

Nathan
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No report.  Working on PhD committee report and slides

Junaid
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New parameters for Hodo Vp for 2021 and 2022
- still need to see if gap in distribution at x=0 is there or not after
  removing HGC cut

Alicia
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Had a meeting yesterday to come up with a plan for the CT "leakage" problem in
10.6 GeV data
- will not affect BSA analysis, except that will have to apply Beta cut before
  selecting random windows

Ali
---
Just returned from Pakistan.  The plan going forward:
- Study Beta cut dependence on data rates and on other variables, to see if the
  CT leakage correction is stable, or not
- will start with Heep data, then move to physics
- will calculate separate corrections for pi/K/p, to see if they're equivalent
  (within errors)

- will calculate the CT leakage correction in the report files, so it will be
  available for all runs in the nxt replay

- Tanja: will the correction determined from only some runs, or all?
  - AU: it depends on what the data show.  We hope it's not rate dependent, but
    we have to check.  Maybe the HeepCoin data give the most reliable
    correction.

Nacer
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Working on selection optimization for KaonLT data @ 3.8 GeV
- copied some output ROOT files from iFarm to local workstation
- Good news: There is no Coin Time vs. Beta tails observed for these data.
- particle ID studies for K+ in progress


Next Meeting
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- Tues Oct 24 @ 15:00 Eastern/13:00 Regina/12:00 Pacific
  - PionLT will go first
  - GH unable to attend, Tanja and Richard will take notes


Poll to select times for Nov-Dec meetings
   https://www.when2meet.com/?21823030-iJ3Eh
Most likely time so far is Thursday afternoon near 15:00 Eastern


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