Kaon_LT Experiment

      Meeting to discuss Kaon-LT Efficiencies for Normalized Yield

                               22-Jun-13

                              (Notes by GH)

Attendees: Stephen Kay, Garth Huber, Ali Usman, Richard Trotta, Vijay Kumar

Richard and Ali

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

- show efficiency plots from new report files

  - EDTM-LT and COMP-LT look consistent with each other, which is good

  - no LT>100%, but that's because the plots are only for COIN data runs

  - EDTM-LT: 95-100% up to ~2kHz COIN-TRIG-Rate.  Then there is a knee at 2kHz,

    and the LT drops rapidly, reaching 80% @ 4kHz

  - GH is a little surprised the knee starts as early as 2kHz, but the LT

    remains above 95% until 3kHz, which is consistent with Carlos' earlier

    study

- tracking-eff, hodo-eff, cher-eff also look pretty reasonable

  - there are some inconsistencies with rate that need to be more closely looked

    at, such as some significantly lower HMS cher-eff.  GH thinks these are likely 

    due to pi- contamination in the electron sample, and the applied cuts should

    be checked more carefully

- the full replay did not include any Lumi or Heep-Singles runs

- also, no aerogel position cuts were applied because they are not set yet

  - we discussed the plot Vijay made earlier of Aero NPE vs x,y to illuminate

    where the position cuts should go.  It is better to place the cuts based on

    the data analysis, rather than numbers from Vladimir, as the aerogel can

    shift in the tray during craning.

- also the Summer 2019 data have not yet been replayed with the new report

  files.  This will wait 1-2 weeks until the aerogel cuts are selected, and

  other checks made.

   - Vijay will have to do similar studies vs run number as Richard & Ali for

     these data

- K+ efficiencies in aerogel

   - K+ need to be selected with a (HGC < npe) cut

   - pions will leak through the (HGC < npe) cut, so a hole cut needs to be

     applied to avoid this region.  Will not cause a problem for the aerogel,

     as its performance is uniform (due to lack of mirrors), but pion leak

     through needs to be minimized, so the cut can be more generous than usual.

   - this means the K+ aerogel efficiency can't be easily calculated in the

     report file, and should be done in the same script used to do the HGC effs

- unlike the aerogel, no K+ efficiencies in HGC need to be applied, due to the

  (HGC < npe) cut

- K+ tracking efficiency

   - GH thinks it will be very difficult to do a K+ tracking efficiency, as the

     statistics will be poor, and you need to worry about pion contamination

   - suggests instead to calculate pion and proton tracking efficiencies and

     see if they are different.  Then apply either the pion tracking eff to the

     K+ data, or the mean of the pion and proton effs

Update on various SIMC issues

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

- Ali followed up on beam energy spread in SIMC

  - Gaskell thinks that it's a non-issue.  0.05% is OK, maybe even too big

- Richard Heep Data/SIMC comparison

  - half of his data had a 40ns CT offset compared to the rest of the same

    setting

  - needed to adjust the offset and replay again

  - data/MC comparisons look much better now

- Ali still tracing differences in Pmiss Emiss calculation between hcana and

  SIMC

  - he feels more inclined to make SIMC calculation the same as hcana than the

    other way around.  Found some issues with over-written variables in SIMC

    (seems a bit strange to GH)

Next meeting

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

- Tue Jun 28 @ 11:30 Eastern, immediately after RC meeting