Kaon_LT Experiment

                  Apr 3/25 PionLT/KaonLT Analysis Meeting Notes

                  ---------------------------------------------

                                (Notes by GH)

                     Today: PionLT will be discussed first

Present

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Regina - Garth Huber, Ali Usman, Alicia Postuma, Muhammad Junaid,

   Nathan Heinrich, Vijay Kumar, Nacer Hamdi

JLab - Dave Gaskell

Virginia - Richard Trotta

CUA - Tanja Horn

Ohio - Julie Roche

FIU - Pete Markowitz

Nathan

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PionLT Lumi Studies

- reviews most important plots for Dave from last week's presentation

  - with CPULT*DM-ELLT, yield increase is ~10%, which is significant

  - correlation with EDTM is similar

- Dave: regarding the EDTM, did you place a tight cut on EDTM TDC?

  - *NB* Nathan will recheck the cut

  - *NB* Richard suggests to also recheck the Trigger Plot to make sure the

    time cut hasn't shifted

- *NB* Dave will look for evidence of Coin Blocking on runs Nathan sent him

- *NB* Nathan will look at correlation vs total DAQ rate (after PreScale)

Junaid

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PionLT Q2=3.85, W=2.62 LT-sep setup

- t-phi plot shows that 0.16-0.50 is reliable t-range based on full phi-coverage

  - it's okay to add one more t-bin past this, not sure whether Rosenbluth fits

    will be reliable or not

- t-resolution plots (SIMC) indicate delta-t=0.0036 at low epsilon, 0.00487 at

  high epsilon, this is smaller than the smallest proposed t-binning so should

  be good

- planning on 15 phi-bins

  - for 7 t-bins, each t-phi bin would have roughly 250 events

  - *NB* we suggest to try 5 t-bins instead, which would give ~350 events/t-phi

- short discussion on NGC scattering simulation in SIMC

  - it is ENABLED by default in simc, look at cer_flat in mc_shms.f

  - *NB* this means we need to DISABLE it for KaonLT analysis (Alicia, Nacer,

    Ali, Vijay take note)

  - this is the opposite default that GH was anticipating

Alicia

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Missed tracks correction

- writing up a TechNote giving instructions on use of G4 code

- Junaid and Nacer will be the first to test it out

Vijay

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PionLT Q2=0.425 LT-sep setup

- t-phi plot shows that 0.007-0.063 has complete phi coverage, but statistics

  might be a bit low past 0.055

  - Vijay will look at narrowing the t-bin range a bit

- reviewing t-dependence of sigT, sigTT parameterization from other papers

Nacer

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KaonLT Q2=0.50 LT-sep setup

- t-resolution plots (SIMC) indicate the resolutino is smaller than the

  smallest proposed t-binning

- t-phi plot to check phi coverage

  - now have 7 t-bins, Lambda: 15k events/t-bin at high epsilon, similar at low

    epsilon

- planning on 15 phi-bins

- writing code to do t-phi binning of data

  - more complex than PionLT analysis in that pion subtraction needs to be done

    separately for each t-phi bin

  - checked a few runs for debugging

  - submitted a job for full replay of one setting

Richard

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KaonLT high Q2 LT-sep

- *NB* everyone should confirm in their SIMC input file that raster_pattern=3

  - Dave: this corresponds to a "flat square" beam spot, =1 corresponds to

    square w/bedposts (see Fig 3.3 of J.Volmer thesis)

- Q2=5.5, W=3.02 iterations

  - t-bin for -t>0.775 ratios are higher than lower -t

  - this is beyond the region of pole dominance, so likely the t-dependence

    needs to be parameterized a bit differently there

  - currently using sigT=p5/(|t|^p6) for all t, might have to add another term

    for higher -t region

  - this would not be done right away, only after preliminary results are available

    - Garth: suggests to only modify sigT this way, since it dominates at

      higher -t, not the L,LT,TT terms

Ali

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KaonLT piDelta BSA

- looking at finer t-binning for only the higher stats settings

- Q2=2.115, W=2.95 study shown

  - Before: 2 t-bins 0.0-0.27, 0.27-0.55, region above >0.55 excluded as Delta

    stats too low there

  - After: 0.0-0.25, 0.25-0.33, 0.33-0.60

  - shows MM per t-phi bin without MC fit, where we are to look at the shape of

    the MM=1.2 Delta region

  - lowest t-bins look good, the highest t-bin will be a bit more challenging

    to fit MC to data, but Ali is optimistic it's okay, particularly given his

    greater experience now in doing the fits

- looking also at adding 1 t-bin to Q2=3.0, W=3.14 setting

- Q2=4.4, 5.5 settings will be unchanged (1 t-bin)

- Q2=3.0, W=2.32 has not yet been looked at, it may or may not have another

  t-bin, will know by next week's meeting

Next Meeting

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- Thur Apr 10 @ 16:30 Eastern/14:30 Regina

  - KaonLT will go first

- NOTE: meetings start 16:30 Eastern/14:30 Regina from March 13-April 10

  - after that, we can return to 15:30 Eastern for the convenience of our USA

    colleagues