Kaon_LT Experiment

                 Nov 15/24 PionLT/KaonLT Analysis Meeting Notes

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                                (Notes by GH)

                     Today: KaonLT will be discussed first

Present

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Regina - Garth Huber, Nathan Heinrich, Alicia Postuma, Ali Usman,

   Muhammad Junaid, Nacer Hamdi

JLab - Dave Gaskell

Virginia - Richard Trotta

Richard

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KaonLT function fitting update for LT separation

- looking only a Q2=3.0, W=3.14 data

- changed t-binning to get more info on t-dependence

  - for now, 10 bins from 0.2 to 0.4

  - after the tests, plan to go to 6-7 bins

  - *NB* GH: t-range 0.2-0.4 is surprisingly narrow, assumes the experimental

    acceptance (after diamond cuts) is wider than this, encourages to use the

    full t-range

- trying a new set of functions for TT

  - TT=(p13+p14*Gaussian)*sin^2(theta) where the centroid and width of the Gaussian

    are free parameters

  - this does a better job of fitting the t-dependence above 0.3, but does not

    have proper form at t-min when p13.neq.zero

  - nonetheless, gives lowest chi-square of all functions tried to date, due to

    better fit for higher -t

  - shows the extracted t-dependence of TT using this function

    - *NB* GH: maybe a 4th order polynomial would do a similar job and have

     better form at low -t?

Ali

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- making good progress on thesis writing, hoping to give 2nd drafts of chapters

  to GH soon

Alicia

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- checked APS author portal for status of BSA paper

  - reports recently received from 2 referees

  - a 3rd referee was contacted on Nov 6 after these two reports were received

- proton absorption MC

  - hoping to have time to work on this next week

Nacer

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KaonLT Heep singles

- offsets were applied incorrectly for singles

  - offset units issue fixed, but maybe still some ambiguity on correct sign of offset

  - *NB* will check w/ Junaid on correct implementation in SIMC input file

- W comparison between Data and MC

  - Ali's resolution tuning parameter has been used

  - cut ranges: 0.8<W<1.05

  - elastic peak comparison looks very good for 3.6-8.4 GeV data, for both peak

    alignment and width

  - 10.6 GeV peak is much wider than other energies, data is shifted compared

    to SIMC

    - *NB* DG: you will need to apply a shift to either data or MC so the peaks

      line up correctly before applying the W-cut

- singles Data/MC yield ratios

  - HMS ratios consistently above 1 (3.8-8.2 GeV beam energies)

  - SHMS also consistently >1

  - DG: very interesting that both Singles and COIN have the same Ratio issue

    - this greatly reduces the number of possibilities on what is wrong

    - *NB* one possibility is that the applied boiling correction is too large

      - applied correction is 8%/100uA from Richard's analysis

      - see 23-Sept-07 RedMine

        https://redmine.jlab.org/attachments/2119

	https://redmine.jlab.org/attachments/2118

  - AU: another possibility is the error in Heep parameterization at higher Q2

    - DG: new high precision Heep cross sections from Hall A have just been

      published, can compare them to SIMC prediction to see if model is off

      - *NB* Dave will look more into this

- Mark's tracking algorithm improvements

  - Mark sent notes on the new procedure earlier this week

  - Junaid thinks it will be straightforward to apply the changes, looking into

  - it

Nathan

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PionLT Lumi studies

- plots of LH2 singles Lumi, combined over all settings

  - results from different settings fall into several categories

  - HMS: red points suggest anti-boiling

    - green+black points are consistent with each other and have flat

      dependence

  - SHMS: green+black points look reasonably consistent

    - red points are weird

    - combined fit (lots of scatter) gives (6.5% +/- 1.1%)/100uA

  - looking into whether it is justifiable to discard the red points

  - not good that SHMS and HMS see different dependences for black+green points

- Coin Lumi analysis using SIDIS+DEMP settings

  - some outliers that need investigating

  - with outliers removed, get two clusters of points:

    - cyan(SIDIS)+yellow(DEMP) -- less boiling (3-4%)

    - black(DEMP)+green(DEMP)+red(SIDIS) -- more boiling

    - blue -- strong anti-boiling

  - still need to investigate rate-dependence, see what is the reason why two

    different correlations seen

    - *NB* DG: should confirm that the target fan speed is the same for all of

      these settings

Junaid

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- working on PhD committee meeting reports

- will implement Mark's tracking algorithm next week

Garth

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- comparing Vijay's Q2=0.38 thesis data to Ackermann Q2=0.35 results

  - some questions that need to discuss with Vijay when he returns

  - working on preliminary fit of VGL model to sigL data

  - outstanding issues:

    - Vijay was looking at changes to LT,TT parameterizations before he left,

      trying to get flatter ratios vs phi for higher t-bins

    - proton absorption correction not yet applied: this will just be a scale

      factor

    - systematic uncertainties not yet included in errors

Next Meeting

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- Thur Nov 21 @ 16:00 Eastern/15:00 Regina

  - *NOTE* meeting time moved earlier by 30 minutes until early January

  - PionLT will go first