Kaon_LT Experiment

                 June 28/23 PionLT/KaonLT Analysis Meeting Notes

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                                (Notes by GH)

                    Today: PionLT 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, Muhammad Junaid, Nathan Heinrich, Vijay Kumar

CUA - Richard Trotta, Tanja Horn

CSULA - Konrad Aniol, Shawn Love

FIU - Pete Markowitz

Nathan Updates

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HGC calibrations

- a few runs last week had a failed fit.  Results shown have most of these runs

  fixed.

PMT2: Two early periods (run ~11,800 and ~13,000) have very different calib

  params (much higher) than the rest (~14,000-16,500)

  - the runs near ~11,800 are when the HGC had bad gas, so not a surprise

    they're different, but the second group ~13,000 are unexpected

  - replaying more runs to fill in the gaps from ~11,800-14,000 to better

    understand the trend

PMT1: similar trend, with two early periods different than the rest, but the

  discrepancy is smaller

PMT4: very similar to PMT1

PMT3: some bad fits that obscure the trend, but after removing these, the trend

  is once again simlar

- good news that all PMTs have same general trend, but the early runs that are

  different than the rest are a puzzle

Next week: 

- expect to finish up the HGC calibs

- trying to set up a meeting w/ Jacob & Junaid on next tasks after calibs done

  - expect NH & MH will split up calorimeter calibs

- will push changes to GitHub after Junaid finishes DC, as he has more files to

  upload

  - NH posting other det calibs to RedMine

Junaid Updates

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DC calibrations

- SHMS LD- data (2022) in progress, everything else done

- plots of residuals and drift distributions

  Blue=old calib  Red=new calib

  - residuals centered at zero and generally sharper than before, double peaks

    gone

  - drift distn plots flat for all planes, looking good

- expecting to be done in the next day or so

  - then will push to GitHub

Richard Updates

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Updated HGC analysis script

- will divide HGC into 3 regions (depending how you count)

  0) inefficient "hole" at mirror overlap will be removed

  1) region near hole that is mid-efficient

  2) rest of the focal plane that has high efficiency

- GH: need to recheck NPE vs XY_hgc for every setting, just to make sure the

  region divisions do not change

  - the Cherenkov cone angle depends on particle velocity, so as SHMS momentum

    changes, the cone angle changes, and this could affect the size of the

    inefficient regions

  - not expecting you will have to re-draw the regions for every P_SHMS, but

    for sure it needs to be checked

  - also, the mirrors were reconfigured in Jan/19, resulting in smaller hole

Luminosity analysis

- Peter's BCM correction has improved the higher current runs, the plot is

  flatter than before, but some points have bad error bars (current cut needs

  adjustment)

- will use HMS ELCLEAN (from physics Lumi scan) for LH2 boiling correction in

  cases where Heep did not provide full coverage

  - will meet with PeterB next week on this

  - GH: since the physics Lumi scan is also supposed to be used for the FADC DT

    correction (according to PeterB), I don't understand how you will be able

    to disentangle using the same data for both LH2 boiling and FADC DT corr

    - RT will discuss this with PB as well

Ali Updates

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- catching up after CAP Congress last week

- rerunning Aerogel Efficiencies for higher NPE cut for K+ PID

HMS Momentum Offsets

- showed DG's plot of offset vs P_HMS determined from KaonLT Heep and XEM

  singles data

  Red=XEM electrons  Blue=XEM protons  Triangles=Ali's Heep results

  P_true = from Heep check  P_nom=from magnet setting

  - both XEM and KaonLT data show same general trend, but the dip in momentum

    offset (to ~0.993) at ~4.5 GeV/c is much deeper for the XEM data

  - DG has confirmed that program that sets HMS magnets is "not significantly

    different" between KaonLT and XEM, despite the two experiments running

    years apart

  - DG believes the sharper XEM dip is due to their not using the latest BPM

    calib

  - however, since XEM singles are not over-constrained, it sounds like they

    are obtaining their offsets from fixing W value, and attributing all

    difference to HMS momentum

    - GH: this assumption may not necessarily be true, if so it could lead to a

      larger offset than Ali, where an over-constrained reaction is used

- KaonLT Heep does not have as many points as XEM singles, so Ali is going to

  look at offsets from Heep singles data

  - likely will have same issue as XEM singles, but at least would confirm

    trend

  - also considering to get offset from PionLT Heep after DC calibs done

Starting to look at LT-separation code

Vijay Updates

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Lumi studies from Summer 2019 data

- got EDTM livetime working

  - only two runs have LT>1.0, but by less than 1 sigma

  - GH: it will be useful to add CPULT to the plot too, so we can compare

HMS calorimeter efficiencies

- working on a plot of efficiency vs P_HMS

  - expecting a drop in efficiency for P<1 GeV/c

  - looking at Heep runs at all 3 epsilon, but also will need to look at the

    physics data to access low P_HMS

  - DG has suggested to keep the cut constant and look at the trend of the

    efficiency

  - GH: try to make plots for fixed cuts: >0.2NPE and >0.7NPE

Next Meeting

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- Thur July 6 @ 16:00 Eastern/14:00 Regina/13:00 Pacific

- KaonLT will go first