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Kaon LT Meetings » mtg_22jul14.txt

Garth Huber, 07/16/2022 09:39 PM

 
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                Jul 14/22 PionLT/KaonLT Analysis Meeting Notes
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                ----------------------------------------------
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                           (Notes by GH and SJDK)
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Please remember to post your slides at:
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https://redmine.jlab.org/projects/kltexp/wiki/Kaon_LT_Meetings
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Present:
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Regina - Stephen Kay, Nathan Heinrich, Garth Huber, Ali Usman, Vijay Kumar,
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   Love Preet
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CSULA  - Konrad Aniol
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Ohio   - Jacob Murphy
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CUA    - Tanja Horn, Richard Trotta
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JLab   - Dave Gaskell
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Richard Updates
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---------------
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- PyRoot-based L/T-separation package
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   - Got the information he needed from Bill's files via Garth's back-up
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   - Changed formatting to fit our efficiency list style a little more
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   - LTSep python package changes
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      - Ver 3.3.0 is latest version
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      - Branches kept are included in runtype
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         - Branch definitions
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         - Grabs required branches
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         - Code runs slightly faster
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         - New version is backwards compatible
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            - Should be able to merge in straightforwardly
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- Comparison of W distributions between MC and Data for 10.6 GeV HeepCoin
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   - Data always lower than MC
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   - changing up to 4 offsets
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   - W should not move in MC, since it knows it's elastic scattering!
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   - Replay didn't shift W with offsets
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      - That's very odd, doesn't seem to be changing in hcana
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      - clearly there is a bug that Richard will need to track
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- Richard 2nd updates
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   - One issue is that Richard is applying the offsets to std.kin, instead of
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     the offsets file.  *This is dangerous*, and was discussed in the
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     22-May-17 meeting, as it can lead to errors and inconsistences.
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     *Much better to use offsets file*
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      - Vijay's replay shifts as expeccted, using the offests file.
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        Ask that Vijay and Richard discuss this offline
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Vijay Updates
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-------------
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- Comparison of various quantities between Heep coin data/MC for 5 energies
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   - No offsets applied
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   - Sees larger shifts in EM, PMx,y,z between Data and MC at 2.7, 4.5, 4.9
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     GeV, and smaller shifts at 3.6, 3.9 GeV
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   - Consistency between similar beam energies between different run periods
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      - The good news is that 3.6, 3.9 GeV behave similarly, even though taken
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        roughly 6 months apart.  i.e. the behavior is reproducible.
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- *Tanja's quick back of the envelope offsets calculation*
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   - For 3.6, 3.9 GeV, momentum offset in electron arm would account for
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     offsets
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   - Larger offsets in other 3 settings, angle offset (~1 mrad) in addition to
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     small momentum offset
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   - EMiss offset -> Need a momentum offset in SHMS (hadron arm): ~0.3% at
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        2.7/4.5/4.9GeV
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   - All settings - 0.1% momentum offset in HMS (electron arm)
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   - 2.7/4.5/4.9 - 1 mrad electron angle offset -> 1 mrad = 0.0573 degrees
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   - a possible reason why the offsets appear to differ at 3.6,3.9 GeV is that
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     the sensitivity to the needed offset depends on the acceptance matching
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     between the two spectrometers for that setting
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      - i.e. does the electron arm (HMS) define the cone of proton coincidences
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        within the proton arm (SHMS), or the other way around, or are they
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        matched?
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      - some settings are better matched kinematically than others.  Best
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       matching occurs when the two spectrometers are near equal angles and momenta.
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Ali Updates
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-----------
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- Brief analysis for increasing range of SHMS delta after discussions with Peter B
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   - Aerogel > 1.5 NPE cut, would need to alter if we increase delta
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      - n = 1.011 aerogel tray does not cover full focal plane and may be
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	   restricting our negative delta acceptance	 
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   - Dave/Stephen point out that the bigger difference will really be on
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	adjusting the HMS delta too 
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      - SHMS and HMS delta correlated, with negative SHMS delta in
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	coincidence with positive HMS delta for exclusive pi+/K+ events
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      - Our online analysis indicates that we would only gain a few percent of
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        exclusive events
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         - HMS delta should NOT be expanded much
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         - Stephen - Older settings should be re-analysed - Delta vs Delta
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	   plots not there previously
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   - GH discusses with PB afterward.  He agrees that this is the case for
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     exclusive events, but he is interested in expanding the delta range for
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     SIDIS events in our data sample.  So this does not sound like it should
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     be a high priority for us.
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- CPULT > 100%
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   - as shown at last meeting, CPULT are OK for COIN replay, but some SHMS
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     CPULT are still over 100%
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   - Changes to report file template
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      - Updated error calculation does not resolve problem
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   - For EDTM, should be using time RAW not time
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   - CPULT should use time (not RAW)
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   - will discuss more about this with Jacob tomorrow
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- When is the aerogel tray changed?
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   - Peter B did not use the run list to determine what aerogel tray is used,
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     but instead looked at the x-y histogram, and placed limits on the edge of
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     the efficient region
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   - he finds some sets of run numbers where he thinks n=1.011 tray is used
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     that differs from Richard's list
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   - the run plan and logbook are unambiguous on when the aerogel was changed.
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     *Ali should independently go through the logbook* to note when aerogel was
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      changed, and see who is right
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- Trying to make EM, PMx,y,z calculations the same between hcana and SIMC
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   - had meeting with DG to understand what variables to look at in SIMC code
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   - Hopefully able to compare to hcana variables shortly
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   - Dave - PMx/PMy/PMz variables in SIMC are just components in the lab frame
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      - In Heep case, PM is translated relative to the q-vector
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      - PMz/PMy, only calculates in-plane components (i.e. those in the
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        central plane of the two spectrometers), ignores out of plane
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        components (i.e. the fact that the q-vector is tilted vertically) 
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      - Thus, the SIMC versions are not really the missing momentum.
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        99% sure this this not the way it's done in hcana
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      - Now that the inconsistency is identified, we need to fix it
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      - Add new variables to hcana?
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         - Or add them to SIMC?
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            - Dave - Probably easier to change SIMC
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         - New variable that is equivalent to SIMC variable in hcana should be
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           easy too 
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   - Two pronged approach makes sense
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      - Tanja suggests to Calculate first by hand and compare
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      - Then decide which one to update
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   - Dave will look into modifying SIMC
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   - *Ali will work on this as a priority*
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- Singles scripts (Heep-singles and Lumi) are ready.  Can replay after calibs done
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Jacob Updates
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-------------
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- In preparation for cutting settings from run plan (i.e. needing to save time
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  due to slow beam start), looking at how many delta scans needed, using
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  KaonLT 2018 data (10.6GeV) with HMS p=6.6 GeV/c
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   - W vs xfp, W vs xpfp and W vs delta comparisons
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   - after optics calibrations are done, the agreement between data and SIMC is
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     good.  Then does predictions for 2022 10.5 GeV delta scan
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   - 3 point scan should be ok: 0 and +/-8%
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      - More stats in -xfp and -delta would be useful -> More in -8% run
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      - Keep overall time the same, shift time from +/4% to +/-8% -> -8% needs
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        ~2x time alloted (roughtly 60% more than 0 setting)
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   - Can cut some settings
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Junaid updates
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--------------
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- not present.  He has adjusted the Heep singles settings in the run plan and
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  distributed a new spreadsheet
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Nathan Updates
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--------------
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- Prepping for Gordon conference
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- Plots for HGC calibration
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   - good fits for PMTs 1,2,4.  PMT3 fits having a hard time
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      - width for 2nd PE peak is far too broad
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      - PMT3 gain is a bit different, peaks closer together
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      - constrain range the width is allowed to vary in for 2nd PE fit?
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      - can try a manual fit to see if it works better
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Next meeting
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-----------
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- 22-Aug-04 at 11:30 Eastern, after RC meeting
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   - Before Gordon Conf, after EIC meeting
(63-63/413)