Kaon_LT Experiment

                Jan 23/25 PionLT/KaonLT Analysis Meeting Notes

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                                (Notes by GH)

                     Today: PionLT will be discussed first

Present

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Regina - Garth Huber, Nathan Heinrich, Vijay Kumar, Alicia Postuma,

   Muhammad Junaid, Ali Usman, Nacer Hamdi

JLab - Dave Gaskell

Virginia - Richard Trotta

CUA - Tanja Horn

Ohio - Julie Roche

FIU - Pete Markowitz

CSULA - Konrad Aniol

Nathan

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PionLT Lumi Studies

- implemented Dave Mack's rate-dependent ELLT calculation

  - ELLT from individual hodo plane gate widths (50ns) and rates

  - implemented in Richard's scaler function for current cuts

    - it's not used for current cuts, but this allows beam-off periods to be

      removed from the rate calculation, tested and the beam-off removal only

      affected the 5th decimal place

  - can easily put the new ELLT calculation in the report file

  - Ali offers to help Nathan w/ report files

- calculated a few runs "by hand" to check

  - Dave Mack's algorithm gets 12.3% for a high rate SHMS run but simple calc

    gave 10.1% (3/4 rate=1.3MHz, S1X rate=3.4 MHz)

  - will implement this ELLT calculation instead of simple calc and check if

    get same LH2 boiling corr for HMS/SHMS scaler Lumi analysis

    - simple calc resulted in too much scatter in SHMS at high rate to be

      useful, could only get boiling from lower rate HMS data

- before implementing DM ELLT calc, had applied rate-dependent correction

  reported earlier to Tracked Singles Lumi data and found consistent

  anti-boiling, so clearly the old ELLT and rate-dep correction is not the

  right way to go

Next steps:

- *NB* will cross-check CPULT*ELLT=EDTM for runs where both quantities are

  reliable

- *NB* will also determine a new boiling corr and apply to COIN Lumi data

Conclusion:

- still lots of checks to do, but we're clearly moving forward

  - optimistic that everything can be wrapped up before departure for WNPPC in

    Banff on Feb 13

Junaid

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Just returned from family trip to Pakistan, getting back to research now

- while away, there has been some further optimization of HMS Matrix Elements

  - will implmement, replay Heep and check

  - after that, will start setting up for Pass-2 replay and Yield calclations

Vijay

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Q2=0.425 data analysis

- showed CoinTime plots from recent replay

- offsets were wrong for certain runs, fixed now

  - low epsilon, Center,Left1,Left2

  - mid epsilon, Center,Left1,Left2

  - high epsilon 5 settings still being replayed

Next Steps:

- still checking other cuts

- *NB* still need to check that efficiencies, etc. are sensible for Q2=0.425

  runs (i.e. checking for bad runs)

Richard

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KaonLT L/T-separations

- last week reported on Q2=3.0, W=2.32 setting, which needed a lot of iteration

  work

- after discussing further with Tanja, decided instead to look more closely at

  Q2=3.0, W=3.14 and Q2=4.4 settings, in particular the Q2-dependence

  - ratios for these settings not there yet

  - Q2-dep seems to be an issue for high Q2 settings

  - expecting to revise Q2-dep for LT,TT

- later, will return to lower W settings, these will probably need extensive

  changes to model

Nacer

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KaonLT Low Q2 Yields

- carefully goes through normalized yield calculation for one setting (low

  epsilon, central SHMS)

  - generally things look sensible, except for the SIMS normalized yield, which

    seems exceptionally high (about 10^6 too high)

- Discussion on what might be wrong with SIMC normalization

  1) check if SIMC weights are correctly applied

    - root tree is structured slightly differently between Heep and Physics runs

     (more variables), maybe the wrong leaf was selected by mistake?

  2) check if SIMC yield and Exp data are both normalized to 1 mC

    - maybe a sign is missing on an exponent 10+3 instead of 10-3?

  3) check what model SIMC is using

    - Dave says default K+ model is still from Koltenuk's thesis (resonance

      region)

    - Garth used Tanja's parameterization for KaonLT run plan yields

      sig_factorized2007, will send it to Dave for including in master branch

    - *NB* Garth still has SIMC ntuples used for KaonLT run plan and compare

       with Nacer's

- MMk plots look very nice after cuts and dummy target subtraction

  - pion leakthrough subtraction underneath Lambda and Sigma peaks look pretty

    good

  - possibly there are some negative counts to the right of the Sigma peak

    (~1.22 GeV), could be a binning issue, need to check if it occurs

    consistently for other settings

  - 50 MeV shift between Data and MC was found and fixed

    - recon.hcana was using mpi instead of mK

    - there remains a small ~3 MeV shift between data and MC, which is applied

      to the data so the Lambda peaks line up

Alicia

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SHMS proton absorption Geant4 calculation

- made some progress

  - S2Y density had a typo and Geant4 had defaulted to zero density

  - now get non-zero energy deposit for Cherenkov process in quartz bars

Discussion of BSA paper referee comments

- 4th referee seems to come from high energy physics, was clearly confused with

  some issues dealing with small acceptance spectrometers that we should

  address so that the paper appeals to a broader audience

  - it would be helpful if we could refer to the SHMS NIM paper for some

    details.  New DOE secretary has imposed a temporary embargo on any new DOE

    publications, reports, or presentations, so the NIM paper can't be released

    until the embargo is dropped (hopefully soon)

  - in the meantime, Vijay suggests we could refer to the Hall C equipment manual

- Alicia will implement our suggestions and have a second round of discussion

  on the paper next week

Next Meeting

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- Thur Jan 30 @ 15:30 Eastern/14:30 Regina

  - KaonLT will go first