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Kaon LT Meetings » mtg_24aug07.txt

Garth Huber, 08/08/2024 05:41 AM

 
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                 Aug 7/24 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, Alicia Postuma, Ali Usman, Muhammad Junaid,
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   Vijay Kumar, Nacer Hamdi, Zach Sullivan
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Virginia - Richard Trotta
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CUA - Tanja Horn
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FIU - Pete Markowitz
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Richard
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-------
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KaonLT functional fits for LT-separation
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- using 1/(W^2-mp^2)^n where n=2
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- applied above W-scaling to Q2=2.1,3,5.5 data and overlaid L,T,LT,TT data for
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  these three Q2 vs t
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  - very interestingly, the initial preliminary separated cross sections lie
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    nearly on universal curves, with very little Q2-dependence at fixed t
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  - this can be used to investigate what might be a good set of functional
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    forms for th L,T,LT,TT fitting
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  - one note of caution is that these separated cross sections are UN-ITERATED,
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    MC/Data ratios are around ~0.5
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- also made plots of Q2-dep at fixed t:
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  -t=0.18,0.24,0.32,0.48 for delta-t<0.05
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- Richard then fit functions to these distributions
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  - sigL monotonically falling with -t, fit looks pretty good
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  - sigT shows a bizarre "diffractive dip" at -t~0.25, fit is not good
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    - some discussion on what to do with this, perhaps best to ignore the
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      diffractive dip structure and try to fit the remaining data and find some
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      function that is adequate
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  - sigTT shows a fairly flat t-dependence, amplitude small
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    - fit diverges at low -t, need to find a function that goes to zero at
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     -t_min
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  - sigLT is negative, as -t increases it first increases in magnitude and then
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    slowly gets closer to zero
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    - the functional form used for TT would actually work reasonably well here
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      *NB* with the addition of an offset, so that it goes to zero at -t_min
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Alicia
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------
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- BSA PRL submitted, received confirmation that it has now been sent to
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  reviewers
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  - this means the editor has found the PRL rationale to be sufficiently good
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    to move to referee stage, which is good news
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- no other report, catching up on other tasks
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Ali
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---
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- no update, working on thesis
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Vijay
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-----
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Low Q2 PionLT LT-separations
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- changing LT,TT functional forms, with goal of reducing phi-dependence of
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  MC/Data ratios
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  - SigLT = p1*exp(p2*t)+p3/t
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  - SigTT = p1*exp(p2*t)+p3/t
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- initial results look very encouraging, high epsilon ratios look fairly flat
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  for t-bins 1-4
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  - t-bin 5-7 ratios still have some oscilations, Vijay has some ideas on how
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    to improve
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  - initial results do not have any iterations
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Nacer
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-----
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KaonLT Heep re-analysis
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- implement Richard's LH2 boiling correction, simple cuts, efficiencies
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- Ratios (in comparison to Bosted parameterization):
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  3.8: 1.016 +/-0.005 (same uncertainty for all)
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  4.9: 1.041
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  6.2: 1.067
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  8.2: 1.112
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  10.6: 1.042
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  - need to understand in particular what's going on at 8.2 GeV
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- plots with Data and MC overlaid
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  - 3.8 agreement looks very good
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  - 8.2: there is an extra "feature" in HMS yptar, SHMS yptar, SHMS delta
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    - MC agrees well with data on left side of yptar distribution
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    - Data has a small extra peak on right side not predicted by MC, what is
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      this?
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  - 10.6: the yptar agreement between data and MC is much better, the extra
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    "feature" seems to be absent, this might be why the 10.6 ratio is much
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    closer to one
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 - Discussion items:
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    - Richard: *NB* try plotting delta vs yptar and look for a correlation
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    - Ali: could it be due to HMS matrix elements?
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      - HMS should not be in saturation region for this setting
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      - the missing feature at 10.6 would dissuade against this explanation
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    - Tanja: *NB* can check if Data and MC are using the same matrix elements
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    - Garth: *NB* maybe the "feature" is an extra source of bkd in 8.2 data
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      - could investigate to see if there is any cut-dependence to this
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        "feature"
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   - Richard: doesn't think this "feature" was present in his Heep data (same
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     runs)
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     - https://redmine.jlab.org/attachments/download/2257/Final_8p2_offset.pdf
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     - *NB* a detailed comparison of Nacer and Richard's plots is needed
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  - *NB* one 8.2 run (7974) has EDTM-LT of 89%, seems low, needs investigation
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Junaid
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------
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PionLT Heep analysis
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- working closely with Nacer to use same methods, corrected the ratio error
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  calculation mistake
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- results look less encouraging that Nacer's KaonLT
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  5.9: 1.054 +/- 0.005
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    - yptar also has the same "extra feature"
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  6.4: same here too
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    - some discrepancies also in xptar, yptar distributions between data and MC
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    - GH: *NB* please check SIMC input file parameters that correct target
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      length, etc are used
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  9.177: R=1.258 +/- 0.014
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    - Pete: *NB* is there something in your applied efficiencies which could
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      an over-normalization of the data?
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      - Junaid pulls up a spreadsheet of corrections to data, and we notice
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        SHMS_Hodo_3/4 Eff is ~89%, *NB* needs investigation
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MM Distributions broader in 2022 than 2021 data
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- plots of RasterY vs EMISS shows a big correlation
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  - *NB* clearly the raster needs to be recalibrated
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  - some raster calibration info is posted at
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    https://redmine.jlab.org/projects/kltexp/wiki/Hall_C_Raster_Information
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Zach
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----
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PionLT Lumi analysis
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- got plotting scripts working after ALMA9 upgrade
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- replaying data now, just started, nothing to show yet
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 Next Meeting
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-------------
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- Thur Aug 15 @ 15:00 Eastern/13:00 Regina
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  - Dave will take notes
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  - PionLT will go first
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