Kaon_LT Experiment

                May 9/24 PionLT/KaonLT Analysis Meeting Notes

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

                                (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, Ali Usman, Alicia Postuma, Muhammad Junaid, 

   Nathan Heinrich, Vijay Kumar, Zach Sullivan, Nacer Hamdi

JLab - Dave Gaskell

York - Stephen Kay

FIU - Pete Markowitz

CUA - Tanja Horn, Casey Morean

CSULA - Konrad Aniol

Vijay

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Low Q2 PionLT LT-separations

- changed functional form:  sigT=A+B(ft_av) where ft_av=t/(abs(t)+0.139570^2)^2

- still using sigL=A*exp(Ct)

- shows results of new iterations:

  - phi distributions at high, med, low epsilon

  - sigT,L,LT,TT versus -t

Alicia

------

Update on pi+n BSA paper

- runs through summary of draft paper on OverLeaf

- asks a few questions on technical details for paper

Tanja

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High Q2 KaonLT LT-separations, shows a few new plots on behalf of Richard

- now including data from Left,Right,Center settings at Q2=3, W=3.14

- lower t-bins have better fit to phi distributions now

- plot of sigL vs -t show evidence of K+ pole, which is great

- sigT is flat, and fairly small magnitude, sigT<sigL for lowest -t bins

  - probably due to large W 

- GH: *some sigT errors look small*, particularly in comparison to sigL, should

  be checked

- now starting to look at Q2=2, W=2.92 data

- draft slides for Richard's China talk on EIC meson structure simulations will

  hopefully be distributed soon

Ali

---

piDelta BSA

- Q2=5.5, W=3.02

  - as before, large -t region (1.05-1.60) is excluded

  - MM fit for 8 t-bins

    - Center: 8 bins, Right: 4 bins, Left: fit done for 2 bins, other 2 bins

      have low stats and narrower MM range, making piDelta fit unreliable

  - first showing of BSA vs phi for these data

    - Bkd subtracted Data (Data-SIDIS-pi+n_tail) is integrated from 1.11-1.4

    - in systematic study, piDelta MC will be integrated as well

    - will make a plot of Bkd subtracted Data to compare to piDelta MC peak

      shape

  - compare BSA to pi+n for 0.4-0.8 t-range, both have magnitudes ~0.1, and

    same sign

- Q2=4.4, W=2.74

  - exclude large t-region: 1.00-1.60

  - Center: 8 phi-bins, pretty good fits

  - Right: fit 4 phi-bins, very low stats in other phi-bins

  - Left: can fit all 4 phi-bins (unlike Q2=5.5)

  - BSA vs phi has magnitude ~0.15, also similar to pi+n for similar t-range

  - Alicia can do a rebinned pi+n BSA for identical t-range to piDelta to make

    the comparison more valid

- work in progress for remaining 3 settings

  - preliminary shape study shown for Q2=3.0, W=2.32

    - exclude large -t 0.90-1.60

    - Right: 8 phi-bins

    - Center: only 6 phi-bins populated

    - Left: 4 phi-bins

Garth

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SIMC mods for pion re-scattering in SHMS/HMS Collimator

- to enable, use the following flags at the end of your input file:

    using_HMScoll = 0     ;  pion scattering in HMS collimator

    using_SHMScoll = 1    ;  pion scattering in SHMS collimator

  - 0=rescattering OFF  1=rescattering ON

- Dave has accepted GH's changes, now in main branch of SIMC

  - confirmed that the effect is small, at least for SHMS

  - GH shows MM comparison plots for two PionLT settings:

      Q2=5.0, W=2.95, eps=0.38, SHMS=center, p_SHMS=6718.9

      Q2=3.85, W=2.02, eps=0.58, SHMS=center, p_SHMS=3493.1

    - only a slight broadening of the MM distribution is seen, slightly more

      for p_SHMS=3.5GeV/c compared to 6.7GeV/c

- Dave mentions that iFarm is transitioning to ALMA-9

  - present version of SIMC will not work on ALMA-9, due to changes in gFortran

    specifications for special structures

  - changes are ready to go, needs to push

  - for now, please be sure you select RH7 nodes

  - RH7 going away completely by end of June

  - longer term, Dave will consider to replace the structures with a more

    conventional storage approach, to avoid the compatibility issue

Nacer

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Low Q2 KaonLT analysis

- downloaded SIMC today and starting to set up for Heep simulations

- found Lumi cryotarget boiling and CAL/Cer Effs with help of Ali

Nathan

------

PionLT Lumi studies

- after updating the BCM calibs, look again at the rate dependence studies

  - runs 16738-16746 1 arm-at-a-time data

  - TLT looks sensible (95-100%)

  - rate dependences generally mild, so optimistic that the studies will go

    well

  - clear evidence that the BCM offsets NH determined earlier will need to be

    revised, most likely a bit smaller, which is good

- 3/4 Trig rate dependent efficiency will need to be added for Scaler analysis

  - some discussion with Dave on not needing to apply this in event analysis, 

    as PID cuts clean things up

- getting Zach a JLab computer account, he will need to do some training first

Junaid

------

- returned late last night from JLab, found the trip to be very useful

  - had a detailed meeting w/Richard on analysis code

PionLT Heep offsets

- will add a systematic error to fit for OOP offset, as GH did for KaonLT

- working on replaying data with in-plane offsets determined by GH

Stephen

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SHMS NIM paper updates

- draft is nearly ready, hoping to be done in time for Quarterly analysis

  meeting in June

- a few more plots needed on performance of aerogel & tracking

  - Nathan and Junaid will follow up

  - some useful plots on NGC performance might be found in Abishek's thesi

Next Meeting

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- Thur May 16 @ 15:00 Eastern/13:00 Regina

  - PionLT will go first