Kaon_LT Experiment

                May 23/24 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

-------

Regina - Garth Huber, Ali Usman, Nacer Hamdi, Muhammad Junaid, Nathan Heinrich,

   Vijay Kumar, Zach Sullivan, Alicia Postuma

JLab - Dave Gaskell

Virginia - Richard Trotta

FIU - Pete Markowitz

York - Stephen Kay

CSULA - Konrad Aniol

Vijay

-----

- implementing Garth's final corrections on Thesis before it goes for committee

  review

- will resume data analysis next week

- first task should be to work on systematic uncertainties table, as it's blank

  in the draft thesis

  - Richard will set up a meeting between Vijay and Nacer to discuss systematic

    uncertainties next week

Ali

---

- also busy with thesis write-up, gave 1 chapter to GH for review

- resuming piDelta data analysis

  - first task will be to finish MM fitting of high statistics settings, plan

    to show results at next meeting

Alicia

------

- pi+n BSA paper is almost ready, planning to circulate it to this group

  tomorrow

  - still need to check PRL word count

  - the uncertainties in the offsets still need to be decided, we will come

    back to this after Junaid's presentation 

Richard

-------

- KaonLT L/T-separations

  - Q2=3.0, W=3.14 -t=0.15-0.5 after 17 iterations presented by Tanja last week

  - Q2=2.115, W=2.95 -t=0.15-0.35 0th iteration result shown

- fitting mean Q2 value per bin vs t value to get general idea of

  Q2(t)=Aexp(Bt) dependence at high, low epsilon, instead of tave factor in

  parameterization

- also looking at fits of mean W value per bin vs t value to replace W-fac with

  a W=mt+b form

  - GH raises a caution: these are the variations in the mean kinematic values

    with t-bin, not the variation in the yields with Q2,W.  They are NOT the

    same, so don't fool yourself when doing this study

- Ali raises the issue of the synchrotron radiation correction to the beam

  energy mentioned by Dave last week

  - GH strongly suspects that this correction was not applied to KaonLT higher

    energy values, it will affect all >8 GeV data

  - it will also affect the offsets, even at low energies, we will discuss more

    after Junaid's presentation.  GH is happy to rerun the offset finder

    program if Richard supplies corrected data

Nacer

-----

- KaonLT low Q2 analysis, working on SIMC-Heep comparison

  - SIMC input files were corrected for offsets, generated files ready

  - now setting up to replay Heep data, trying to solve a problem w/missing BCM

    file, probably caused by incorrect pathing, will meet with Ali on this

Nathan

------

PionLT BCM calibration study

- looking at quadratic correction for BCM2

2021 Lumi data: 

- if quadratic term included, the Lumi scan looks flatter vs current, but still

  not perfect

- then allow fit function to refit BCM slope + offset while keeping quadratic

  term fixed

  - result is a slight over-correction with current, but the best result

  - will use this one.  Dave agrees this looks good

2022 Lumi data:

- when quadratic term is added, the Lumi scan is better for >60uA, no

  difference below this

- refitting slope + offset while keeping quadratic fixed gives an over

  prediction at high current, and low current is now too low

  - this is not as good as just adding the quadratic term to simple linear fit,

    so will use that one

  - 2021,22 calibs look very good, just waiting on feedback from Dave Mack

- started looking at Lumi analysis w/ new BCM calibs

  - supervising Zach to get him started on Lumi analysis

  - a jump in TotalLT (TLT) is observed at 40uA for Carbon runs 12144-12154

    - Dave: consider using CPULT instead of TLT for these runs

    - NH: CPULT is not always more reliable, shows Carbon runs 16727-16737

      where CPULT~81% but TLT~99%

      - need to check if there's a script bug causing this, since the script

        assumes 2-arm data, but these runs are 1-arm

      - Ali: suggest to compare CPULT from Report File to value from script

Junaid

------

PionLT Heep-Coin analysis

- corrected all beam energy values for synchrotron radiation after Dave's

  comment last week, and then reran Heep + SIMC

  - only has an affect for >8 GeV, correction is zero below that

- GH generated new offsets from corrected data, Junaid shows comparison

  - new offsets have SHMS and HMS momentum offsets near zero, which is good

  - comparison of trend in beam offsets is interesting:

    - the new beam offsets are typically -0.5x0.1% while the old ones are

      0.1x0.1%, so a systematic difference of -0.6x0.1%. 

    - however, both sets have the same 0.6x0.1% jump between 9.879 and 10.550

      GeV, i.e. 0 to +0.6x0.1% old, and -0.6x0.1% to 0 new

  - Junaid will replay data + SIMC to be sure offsets are applied correctly

    - also will compare old and new offset results for 5.984, 7.937, 10.549 GeV

- now back to Alicia's question about offset uncertainties

  - based on the difference between the two offset solutions, GH suggests

    0.5x0.1% for energy & momentum offsets, 0.5x1mr for angle offsets

    - Dave agrees this is sensible

Stephen

-------

- iFarm transition from RH7 to ALMA9

  - Ole Hansen sent out an email on pre-compiled packages:

    "As many of you know, we are providing precompiled software under

    /group/halla/apps. Much of this software has been built for both RHEL7 and

    Alma9 and can be loaded with the "module" command on either

    platform. Specifically, the following modules support Alma9 at this time:

      analyzer/1.7.12

      analyzer/1.7.8

      boost/1.84

      CLHEP/2.4.6.4

      evio/5.3

      Geant4/11.1.2

      Geant4/11.2.1

      hcana/1.1

      Pythia/6.4.28

      Pythia/8.311

      python/2.7.18

      Qt/5.15.10

      Qt/5.15.13

      ROOT/6.26-10

      ROOT/6.30-04

      xerces-c/3.2.4

      group.apps

   "For reference, here is an example of how to set up the Hall C analyzer on

    the central systems:

      % module purge

      % module use /group/halla/modulefiles

      % module load hcana

      Loading hcana/1.1

      Loading requirement: pythia6/6.4.28 pythia8/8.311 root/6.30.04 evio/5.3 analyzer/1.7.12

   "(The pythia requirements appear because ROOT/6.30.04 was compiled with

   pythia support.)"

  - Stephen could get hcana to compile, did not yet try LTsep package

  - Nathan could not get hcana to compile

Next Meeting

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

- We will cancel next week's meeting due to various time conflicts

- Next meet: Thur June 6 @ 15:00 Eastern/13:00 Regina

  - PionLT will go first