Kaon_LT Experiment

                 July 27/23 PionLT/KaonLT Analysis Meeting Notes

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                                (Notes by GH)

                     Today: PionLT 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, Muhammad Junaid, Vijay Kumar, Portia Switzer, 

   Nathan Heinrich, Alicia Postuma

CUA - Richard Trotta, Tanja Horn

JLab - Dave Gaskell, Peter Bosted

Ohio - Julie Roche

CSULA - Konrad Aniol

Junaid Updates

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HMS Calorimeter calibrations

- updated Cherenkov cut from 5->7 pe and delta cut now +/-8%

- still getting wiggles in delta vs Edep/P at high delta

- wiggles worse at 2.2 GeV/c than 3.8 GeV/c, but still present

- DG: it looks like we're going to have to live with it, will have to make calor

  cut a bit broader than otherwise, but #pi- is small anyways

- PB: why are you calibrating run-by-run?  If you calibrate too much, you will

  actually introduce a false dependence to the data

  - better to look at the position and width of the calor peak and decide from

    there whether its stable or need to re-calibrate

  - if the efficiency of the E/P cut varies <0.1% it's good enough

- DG: the calibration will change with momentum and rate (such as changing

  target).  The PMTs are not optimized for high rate >100kHz

- GH: expect we should only have to calibrate for every setting, as DG suggests

  - can look at E/P for different sections of the focal plane (e.g. bin in 2%

    delta), and look for changes corresponding to >0.1% cut efficiency change

Nathan Updates

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HGC calibrations

- was away camping Sat-Wed, so not much done last week

- HGC calib params vs Run#

  - DG asked DMack his opinion, might have been due to too high rate on HGC

    PMTs, leading to gain dep, suggests running at lower HV, particularly when

    SHMS at very forward angle

- param files will be put into standard.database

- NH considering whether calib discontinuity synchronizes with a setting

  change, and adjust the step functions accordingly

  - many are associated w/5.5deg running, as DMack suggests

  - NH hasn't made a final decision on this yet

- JR: how did you choose which runs to analyze?

  - each point is a whole setting, which is placed at the Run# corresponding to

    middle of setting

Next tasks (after HGC calib implemented & documented):

- help JM w/ calor calib

- also continue checks on standard.kinematics

Vijay Updates

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No report, was working on writing thesis (systematics chapter)

- plans to get plots of TrackEff and other Effs before starting Lumi study

- hopes to have these plots in 1-2 weeks

Richard Updates

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Editing Yield Calc code

- lots of discussions w/Ali this week

- adjusted code to do random & dummy subtractions for each (t,phi) bin

Finishing up Geometric cut for HGC in SIMC

- also Aerogel cut to select part of Focal Plane where aerogel actually is

  (based on npe plot vs X,Y)

- PB: please let him know the final aerogel cuts used, as he found that the

  tray cut differs from the geometry info from Vardan

Placing detector cuts in hcana/SIMC

- PB: best to apply cuts to SIMC data, not in SIMC itself, turned all flag cuts

  off, then placed a cut on calorimeter position (projected a few cm from the

  front, not at the face location)

- DG: In hallc_replay_lt there’s a cut 5 cm from the edge of the calorimeter

  (top and bottom) and left and right.

  - RT: Great, thanks Dave. So I really just need to uncomment it in SIMC and

    should be set with calorimeter geo cuts

  - DG: And check what the cut is in SIMC

Alica Updates

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It has been decided that AP and AU will have different t-bins

- question is what kind of binning is needed?

- we look at plots of sigLT' vs -t, and plots of BSA vs. phi

- the asymmetry vanishes in parallel kinematics (-t_min) and grows with a

  "square root like function" for (t-t_min)>0

AP will try smaller -t bins near -t_min, will also look at reducing #phi bins

- PB: uses 15 phi bins, someone convinced him earlier that an odd number of

  bins is best, for low stats he uses 9 bins

JR: how did the meeting with Pawel Sznajder (Nat.Cent.Nucl.Res. Poland) go on

  PARTONS implementation?

- we met last Friday.  Implementing cross section into the code framework is

  less straightforward than the asymmetry, which is why it hadn't been done

  yet, but it should be possible

- showed him the discrepancy we see compared to prior calcs we received

  directly from Kroll, he will investigate.  Prefers if he do the

  implementation himself, rather than AP, so that the correct framework is

  utilized.

- told him there is a lot of interest in these calcs, would really want them

  implemented in the official version, so we don't have to repeat it in next

  version

Portia Updates

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DeltaPi MM spectra for Q2=4.4, center data for 6 phi bins

- SIDIS MC overlaid on data, but the SIMC was not binned in phi

- PB: you need to bin the SIMC events in exactly the same way as the Expt data

  so that acceptance effects are taken into account

- GH: treat data & MC in the same way for Left,Center,Right settings, fit SIDIS

  and DeltaPi SIMC dists to the data (to get the shape) for each, and subtract

  - only after the DeltaPi yield is found for each bin for Left,Center,Right

    separately, do you combine them in an error-weighted average

- AP: the plan will be to have MM plots with SIDIS and DeltaPi MC included, for

  each t,phi bin, in 2 weeks

Next Meeting

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We do not yet know whether our next meeting will be Aug 3 or 10, as it depends

on whether DG is available on Aug 3.  GH/NH/JM/AP will be on a hiking trip in

the Canadian Rockies

- Thur Aug 3? @ 16:00 Eastern/14:00 Regina/13:00 Pacific

- KaonLT will go first

Also, please note that our last Zoom reservation for this time is Aug 17.  GH

will circulate a poll to see if everyone is still available at this time for

the fall semester