Kaon_LT Experiment

                 Aug 7/24 PionLT/KaonLT Analysis Meeting Notes

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                                (Notes by GH)

                     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, Alicia Postuma, Ali Usman, Muhammad Junaid,

   Vijay Kumar, Nacer Hamdi, Zach Sullivan

Virginia - Richard Trotta

CUA - Tanja Horn

FIU - Pete Markowitz

Richard

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KaonLT functional fits for LT-separation

- using 1/(W^2-mp^2)^n where n=2

- applied above W-scaling to Q2=2.1,3,5.5 data and overlaid L,T,LT,TT data for

  these three Q2 vs t

  - very interestingly, the initial preliminary separated cross sections lie

    nearly on universal curves, with very little Q2-dependence at fixed t

  - this can be used to investigate what might be a good set of functional

    forms for th L,T,LT,TT fitting

  - one note of caution is that these separated cross sections are UN-ITERATED,

    MC/Data ratios are around ~0.5

- also made plots of Q2-dep at fixed t:

  -t=0.18,0.24,0.32,0.48 for delta-t<0.05

- Richard then fit functions to these distributions

  - sigL monotonically falling with -t, fit looks pretty good

  - sigT shows a bizarre "diffractive dip" at -t~0.25, fit is not good

    - some discussion on what to do with this, perhaps best to ignore the

      diffractive dip structure and try to fit the remaining data and find some

      function that is adequate

  - sigTT shows a fairly flat t-dependence, amplitude small

    - fit diverges at low -t, need to find a function that goes to zero at

     -t_min

  - sigLT is negative, as -t increases it first increases in magnitude and then

    slowly gets closer to zero

    - the functional form used for TT would actually work reasonably well here

      *NB* with the addition of an offset, so that it goes to zero at -t_min

Alicia

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- BSA PRL submitted, received confirmation that it has now been sent to

  reviewers

  - this means the editor has found the PRL rationale to be sufficiently good

    to move to referee stage, which is good news

- no other report, catching up on other tasks

Ali

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- no update, working on thesis

Vijay

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Low Q2 PionLT LT-separations

- changing LT,TT functional forms, with goal of reducing phi-dependence of

  MC/Data ratios

  - SigLT = p1*exp(p2*t)+p3/t

  - SigTT = p1*exp(p2*t)+p3/t

- initial results look very encouraging, high epsilon ratios look fairly flat

  for t-bins 1-4

  - t-bin 5-7 ratios still have some oscilations, Vijay has some ideas on how

    to improve

  - initial results do not have any iterations

Nacer

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KaonLT Heep re-analysis

- implement Richard's LH2 boiling correction, simple cuts, efficiencies

- Ratios (in comparison to Bosted parameterization):

  3.8: 1.016 +/-0.005 (same uncertainty for all)

  4.9: 1.041

  6.2: 1.067

  8.2: 1.112

  10.6: 1.042

  - need to understand in particular what's going on at 8.2 GeV

- plots with Data and MC overlaid

  - 3.8 agreement looks very good

  - 8.2: there is an extra "feature" in HMS yptar, SHMS yptar, SHMS delta

    - MC agrees well with data on left side of yptar distribution

    - Data has a small extra peak on right side not predicted by MC, what is

      this?

  - 10.6: the yptar agreement between data and MC is much better, the extra

    "feature" seems to be absent, this might be why the 10.6 ratio is much

    closer to one

 - Discussion items:

    - Richard: *NB* try plotting delta vs yptar and look for a correlation

    - Ali: could it be due to HMS matrix elements?

      - HMS should not be in saturation region for this setting

      - the missing feature at 10.6 would dissuade against this explanation

    - Tanja: *NB* can check if Data and MC are using the same matrix elements

    - Garth: *NB* maybe the "feature" is an extra source of bkd in 8.2 data

      - could investigate to see if there is any cut-dependence to this

        "feature"

   - Richard: doesn't think this "feature" was present in his Heep data (same

     runs)

     - https://redmine.jlab.org/attachments/download/2257/Final_8p2_offset.pdf

     - *NB* a detailed comparison of Nacer and Richard's plots is needed

  - *NB* one 8.2 run (7974) has EDTM-LT of 89%, seems low, needs investigation

Junaid

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PionLT Heep analysis

- working closely with Nacer to use same methods, corrected the ratio error

  calculation mistake

- results look less encouraging that Nacer's KaonLT

  5.9: 1.054 +/- 0.005

    - yptar also has the same "extra feature"

  6.4: same here too

    - some discrepancies also in xptar, yptar distributions between data and MC

    - GH: *NB* please check SIMC input file parameters that correct target

      length, etc are used

  9.177: R=1.258 +/- 0.014

    - Pete: *NB* is there something in your applied efficiencies which could

      an over-normalization of the data?

      - Junaid pulls up a spreadsheet of corrections to data, and we notice

        SHMS_Hodo_3/4 Eff is ~89%, *NB* needs investigation

MM Distributions broader in 2022 than 2021 data

- plots of RasterY vs EMISS shows a big correlation

  - *NB* clearly the raster needs to be recalibrated

  - some raster calibration info is posted at

    https://redmine.jlab.org/projects/kltexp/wiki/Hall_C_Raster_Information

Zach

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PionLT Lumi analysis

- got plotting scripts working after ALMA9 upgrade

- replaying data now, just started, nothing to show yet

 Next Meeting

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- Thur Aug 15 @ 15:00 Eastern/13:00 Regina

  - Dave will take notes

  - PionLT will go first