Kaon_LT Experiment

                 Jul 11/24 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, Nathan Heinrich, Zach Sullivan, 

   Nacer Hamdi, Muhammad Junaid, Vijay KUmar

CSULA - Konrad Aniol

JLab - Dave Gaskell

FIU - Pete Markowitz

Virginia - Richard Trotta

CUA - Tanja Horn

Ohio - Julie Roche

Vijay

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Low Q2 PionLT Systematic Studies

- SHMS acceptance cuts +/-10%

  - delta, xptar, yptar changed together

  - variations in L,T,LT,TT are small

  - Dave: you should change the cut in each variable one at a time

    - want to treat the uncertainties in each variable as uncorrelated, and

      then add them in quadrature

    - changing all variables simultaneously implies the 3 quantities are

      correlated

    - *NB* this means 6 changes in total for each spectrometer

- changing sigLT functional form in LT-fit

  - Exp/MC ratios at high epsilon have a pronounced cos(phi) dependence

  - will modify functional form to see effect

  - currently have sigLT=(A*exp(Bt)+C/t)*sin(theta*)*g(W)

  - the C/t term was not in functions used in prior papers, will try just C as

    a fit constant

Richard

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High Q2 KaonLT LT-fitting

- using sigL=(P1+P2*logQ2)*exp(P3*t), sigT=(p5*(t/Q2-1))*exp(P6*t)

- using same sigLT equation as Vijay

- will show only 1st iteration for all settings

- will concentrate on lower -t region now to try to get a good fit, but will

  need to do full t-range later for K-pole tests

- given these caveats, initial sigL,T shown for:

  Q2=2.115,W=2.95    Q2=3.0,W=3.14    Q2=5.5, W=3.02

  - will look at replacing (t/Q2-1) term in sigT with (t/Q2-P7)

- Dave: Exp/MC ratios have some weird sin(phi) dependence, implies something

  very weird is going on, not just an interference function issue

- Garth: suggests doing a few more iterations and plotting P1-P6 vs Q2 to see

  what kind of Q2-depenence results

  - *NB* then use this info as feedback for what kind of fuctional form to try

  - Henk and GH used this approach in Fpi-1 pi-/pi+ analysis and it was useful

Alicia

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pi+ BSA analysis

- some comments have been received on the paper.  <10% of collaboration has

  responded

- shows slides for Monday's presentation for comment

Nacer

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KaonLT Heep Exp/MC ratios

- *NB* will try modifying Heep model in SIMC to see if this helps higher beam

  energies

- GH will send the routine that Bill used in his thesis

Nathan and Zach

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PionLT Lumi Studies

- HMS, SHMS carbon scans 16738-16746

  - changed BCM offset by 9nA (0.025uA -> 0.034ua) and low current dependence

    looks flatter now

  - reduced chi-square is calculated for different fits of rel.yield versus

    beam current

  - adding a slope results in overfit (too small chi-square), while a flat line

    fit gives chi-square closer to 1 (although as low as ~0.5 for some plots)

  - *NB* conclusion is that carbon scans look good and flat.  GOOD NEWS!!

- HMS LH2 scans 16703-16712

  - high current point is much lower than the others, there is at least 1

    outlier, maybe two

  - would imply little boiling at low current, with significantly more boiling

    at 80uA

  - no fits to rel.yield versus beam current are good, chi-square bad for both

    flat fit and linear drop

  - investigating possible problems:

    - Total Live Time (TLT) shows linear drop to 92% at 120 kHz

    - CPULT also drops linearly, but is ~80% at low rate instead of ~100%

  - need to recheck how CPULT is calculated, might be including DTM events

  - Dave: you should be able to form CPULT for different trigger legs

    - *NB* this used to be in the report files, take a look at an old version

      of the template for the calculation

- SHMS LH2 scans 16759-16764

  - larger errors than the HMS scan but looks similar

  - notably, the highest 80uA point is an outlier here too (although perhaps

    not by as much)

- GH: *NB* suggest to add a small quadratic term to fit versus current

  - since both spectrometers see similar behavior, it might be real

- Dave: target fan speed seemed to change a lot in early 12 GeV expts, makes a

  big difference to the LH2/LD2 boiling, so that's why different early

  experiments repot large variation in observed boiling

  - Tanja: *NB* Josh did a study of target characteristics versus fan speed,

    try to get a copy of his report

- 2021 Lumi scans

  - Zach starting to set up for doing the 2021 scans

  - Nathan reports that the analysis script should hopefully work for 2

    spectrometer singles runs, as it is based off Richard's original script

  - it would be helpful to see how different the results are, partly to

    establish the systematic uncertainty in the Lumi scans

- Coin Lumi scans were also taken in PionLT

  - Nathan's old code would have to be fixed for these studies

Junaid

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PionLT HeeP studies

- results for all 9 settings shown

  - includes offsets from Garth and Nathan's BCM calib

  - Richard has sent new version of recon_hcana script, will check if this

    makes any changes

- 5.988 GeV energy Exp/MC distribution comparisons look quite good

- 6.399 GeV Ratio<1 by about 1.5 sigma

- 7.942 GeV Ratio=1.118

- 8.483 GeV Ratio=1.147

- 9.177 GeV Ratio=1.261

- 9.884 GeV Ratio=1.156

- 10.547 GeV Ratio=1.232

  - clearly a systematic trend to the ratios (with some noticeable fluctuation)

  - rechecking error calculation on the ratios

- proton absorption correction not yet implemented to Exp yields, but this is

  expected to make the ratios worse

- there is an issue with 2 of the Dummy Target runs

  - very small number of events after replay

  - got same answer for both RH7, ALMA9 versions of hcana

  - gets a map warning when doing replay, consulting w/ Mark Jones on this

 Next Meeting

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- Next meet: Thur July 18 @ 15:00 Eastern/13:00 Regina

  - PionLT will go first