Kaon_LT Experiment

                 Feb 29/24 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 - Nathan Heinrich, Muhammad Junaid, Ali Usman, Garth Huber, Vijay Kumar,

   Nacer Hamdi, Alicia Postuma

CUA - Richard Trotta, Casey Morean

JLab - Dave Gaskell

FIU - Pete Markowitz

Richard

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- PhD thesis has now been submitted to the committee for review.

  Congratulations on this milestone!

LT-Iteration Script Issues

- uncertainties for unseparated d2sigma behave weirdly when iterating, while

  the R=model/data ratios behave normally

  - statistical errors on d2sigma get much smaller after an iteration

  - clearly there is still a bug somewhere

  - GH: it sounds like the way the R-error is propagated to d2sig-error is the

  issue

Plots of d2sigma vs phi are shown for various settings at high, low epsilon

- a MM cut is now applied: 1.1<MM<1.18

- Q2=3.0, W=2.32 is particularly weird, low epsilon significantly larger than

  high epsilon

  - for this setting P_HMS=6.6 GeV/c, so maybe that's a hint

  - Ali: the Heep offsets for this setting over-correct the MM peak, i.e. moves

    it too far

Plots of sigL, sigT vs t shown

- for some settings -sigL is plotted instead of sigL, due to the low

  epsilon>high epsilon issue

- clearly this will need significantly more investigation

Ali

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- was sick last week, only getting back on track now

Clean pi+,p data for Richard's PID leakage subtractions

- finished analyzing pi+ for 3 of 5 kinematics, data ready for RT subtraction

- proton will be done soon

- no HGC cut used at all

  - RT will apply the HGC hole cut to his sample, confirms that it will be

    straightforward to implement

  - RT still has to resolve the 5cm HGC hole cut shift issue reported a few

    weeks ago

    - RT thinks the x_HGC, y_HGC coordinates were not implemented correctly,

      will return to this soon

Resuming SIMC resolution study, nothing to report yet

Alicia

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HMS-delta correction update

- had a discussion with DaveG a few days ago, after finding that application of

  DG's delta-correction did not yield the expected improvement to MM resolution

  - found that DG's MM calc was based on the old 6GeV/ENGINE formula

  - Alicia is using hcana calculation, and this appears to be the cause of the

    difference

  - DG is trying to figure out what exactly is different between the two MM

    calculations

  - hcana: takes x',y' and spectrometer angles, converts to spherical theta,phi

    and calculates PM components

  - ENGINE: calculates PM components in spectrometer x',y' system and converts

    to target coordinates, but does not use spherical coordinates at any step

  - DG: calc in hcana is harder to follow, can't see where the difference is,

    in principle both calculations should be equivalent

  - AP: tried to recalculate MM on her own, also agreed that old method is

    easier to understand

    - her calculation does not fully reproduce hcana either

- Alicia shows a plot from script, sees no correlation between delta and hsxpfp

  for P_HMS<5 GeV/c

  - Q2=2.1, W=2.95, P_HMS=5.292: starts to see a correlation

  - Q2=3.0, W=2.32, P_HMS=6.59: a definite curved correlation is seen

  - will have to apply a correction for these two settings, but it needs to be

    different than what DG had found

  - DG: for P_HMS=6.59, are we 100% sure we're using the correct Matrix

    Elements for this setting?

    - Ali goes to check, confirms that the correct ME are used for both his and

      Alicia's analyses

    - Jacob was looking at finalizing the high HMS momenta ME, Holly is looking

      at higher P_H MS w/NPS students

      - clearly there is an issue that needs further optimization

- Implementing the HMS-delta correction for high P_HMS

  - DG: can't just correct MM, all kinematics are affected, in principle will

    affect the t-binning for these settings, as events will migrate from one

    bin to another

  - rather than Alicia continuing with her reconstruction script, it will be

    better to modify hcana to include the correction for high P_HMS, so that

    all kinematics are handled consistently

  - DG: suggests fitting a quadratic, but only apply to a certain region of the

    HMS focal plane

  - Alicia: maybe a piece-wise linear function?  Will think about what works

    best

  - *CONCLUSION* Alicia will first determine the needed delta correction then

    implement in hcana

Vijay

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- Just returned from EIC workshop in India, starting analysis again and yield

  ratios

Shows interesting Lattice QCD calculation from workshop

- Swagato Mukherjee (BNL), Q.Shi will be first author, not yet submitted

- LQCD calc for both pi+ and K+ to Q2~35

  - calc indicates that both Q2*Fpi and Q2*Fk will remain high through the full

    Q2 range, with no significant decrease to pQCD curve

    - not surprisingly, the Lattice errors are fairly large

    - we definitely need to keep a look out for the final calculation

Nathan

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Working on PionLT Lumi study and plots for the SHMS NIM paper

- looking at what PID cuts to apply for the Lumi study, which also generates

  the needed plots for the paper

- SHMS single arm e' Lumi scan

  - NGC vs Calorimeter

  - NGC vs Aerogel

  - NGC vs HGC

  - GH: suggests to apply NGC vs Calor cut and look at the others with this cut

    applied to see what is removed before deciding whether the other plots add

    anything extra to the PID selection (useful also for the paper)

- HGC, NGC efficiencies vs delta

  - efficiency plots vs X_cer still in progress

- HGC, NGC, Aerogel 2D efficiency plots vs X,Y_FP

  - see hole in the HGC, NGC and tray boundaries in Aerogel

- LH+ production data PID plots shown

  - LD- also quickly looked at, sees large e- peak in SHMS

Next Steps:

- make sure sure Lumi script is working properly

  - RT will meet with Nathan separately to go over what changes he needs to

    make to Lumi script

  - In addition to changes since 2021, Nathan will have to modify the script to

    handle Lumi runs where only one arm data at a time (should be straightforward)

- apply proper cuts on data ranges

Junaid

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Working on PionLT efficiency studies

- investigating outlier runs, removed bad runs from plots

  - most of these had beam trip issues

  - also some runs with quadrupole trips

  - DG: how do you remove these runs from the analysis?

    - run list is modified, so these runs will never be replayed in future jobs

- tracking efficiency studies nearly complete

- generating beam cut files from replays

  - will be included in future replays

Heep-check analysis preliminaries

- looked closely at the kinematics for all Heep-Coin settings in 2021-22

  - selected 9 of the 16 settings for further study, based on the angle and

    momentum settings

  - GH: the other 7 settings will be kept in reserve for a future student to

    look at

  - did not look at list of Heep-singles runs yet, it's a very large list of

    settings

    - will first look at the Heep-coin results and from there decide which

      Heep-singles settings are helpful to look at

Nacer

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Efficiency studies for 3.8, 4.9 GeV KaonLT data

- Plot of CPULT vs COIN trigger rate

  - sharp drop off seen above 2.8 kHz

  - looked at the outlier run near 2.8 kHz, where the CPULT relation kink

    - no comment in run sheet, will look next at hclog

  - DG: are the rates corrected for the beam off time?

    - will have to look more closely into this

- Plot of SHMS_pion_sing_TrkEff

  - vs SHMS_3/4 trigger rate

    - 2 outliers seen

  - vs S1X rate

    - 3 outliers seen

Next Meeting

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- Thur Mar 7 @ 15:00 Eastern/14:00 Regina

  - PionLT will go first

- USA daylight savings switch is following week

  - meeting time will remain at 15:00 Eastern, which switches to 13:00 Regina

  - GH will send Zoom invitations up to end of August