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Kaon LT Meetings » mtg_23mar23.txt

Garth Huber, 03/24/2023 08:41 PM

 
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                 Mar 23/23 PionLT/KaonLT Analysis Meeting Notes
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                 ----------------------------------------------
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                               (Notes by GH)
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                    Today: PionLT will be discussed first
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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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-------
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Regina - Garth Huber, Ali Usman, Alicia Postuma, Muhammad Junaid, Nathan
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   Heinrich, Vijay Kumar
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ODU - Carlos Yero
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JLab - Dave Gaskell
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CUA - Richard Trotta, Tanja Horn
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Ohio - Julie Roche
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Carlos Discussion
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-----------------
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Carlos has agreed to attend and present some of his Lumi scaler analysis
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results, so he goes first
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Carlos discussed scaler analysis results with Richard, and also redid some
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KaonLT lumi scaler analysis
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- plots of T1(SHMS-3/4)/mC, Runs 5157,56,55,54 positive polarity runs
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   - sees steep rise with current to 55uA
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- plots of T3(HMS-ELREAL)/mC, same runs (electron polarity)
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   - sees flat dependence with current
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- also plots T1 vs scaler rate, T3 vs rate
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   - expects an increase with rate because of increasing randoms and scalers of
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     course can't eliminate them
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Carlos shares his findings from CaFe analysis:
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- motivation is to understand why there is a drop in yield (counts/mC) with
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  beam current observed in CaFe results.  The yield has been corrected for
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  HMS/SHMS track eff, total LiveTime
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His slides on relative yields rate dependence are available at:
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https://hallcweb.jlab.org/DocDB/0012/001209/001/rate_dependence_slides_cyero_Mar09_2023.pdf
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Slides on Event Type Definitions at:
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https://hallcweb.jlab.org/DocDB/0012/001208/001/event_type_definitions_COIN_DAQ_cyero_Mar16_2023.pdf
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   The slides on event type definitions might be helpful when trying to
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   understand how to properly select which event types based on whether
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   singles or coincidence was taken, and how to extract the singles and
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   coincidence separately. This is sort of complementary to Jacob's EDTM
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   studies.  It might help in selecting the right event types when calculating
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   EDTM live times for singles, in which case you would need to apply the
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   proper event type cuts.
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- in CaFe trigger config, T5 (coin) is formed by overlap of SHMS (T2) and HMS
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  (T3)
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   - 1st hit in look-back window gets selected and is used by the analyzer to
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     form a coincidence time (i.e. T2-T3)
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   - it is needed to set a cut on the raw TDC spectrum for the relevant
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     channels (T2, T3), otherwise an accidental at arrives first in the
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     look-back window will "block" the real coincidence
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       - generic parameter file: PARAM/TRIG/tcoin.param
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   - coincidence time (corrected for path length) without this cut looks
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     drastically worse than one with properly set cuts
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   - also, the number of events with good CoinTime is higher with good cuts, as
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     fewer coincidences are blocked by accidentals
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- the relative yield from Be9 target versus current is MUCH different after the
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  cut is optimized
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   - BEFORE: ~7% decrease in yield is observed to 60uA
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   - AFTER CUT OPTIMIZATION: the relative yield is nearly flat with current, at
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     most a ~1%(+/-1%) effect
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- Conclusion: it is EXTREMELY IMPORTANT to verify that these cuts are set
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  correctly (see his example TDC spectra) as otherwise there will be a large
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  rate dependence and it will be hard to diagnose what is wrong!
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Richard Continues this Discussion
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---------------------------------
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- Nscaler = sum(trig scaler) - EDTM_scaler
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- Yield_scaler = Nscaler/Q
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- runs 5154-58, 5298, all same setting
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Compare Richard & Carlos results
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- two main differences
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   1) when using same current cuts as Carlos, linear dep is restored, same as
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      Carlos
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   2) HMS: RT gets linear increase ~5%, while CY sees flat
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      - also RT gets rates up to ~100kHz, while CY has rates to 60kHz FOR SAME
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        RUNS
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- CT data are middle 4 of RT's 6 runs
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** RT, CY will meet to compare exact HMS scaler values on Friday, and see where
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   the rate discrepancy is coming from.  Ali will join online
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** Nathan will check PionLT data to see that trigger cuts that Carlos described
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   are set correctly
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** it is important for RT, VK can confirm that these cuts are set correctly on
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   KaonLT and Summer-2019 data
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- check both TDC and yield vs current for a solid target
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- CY: also be sure that EDTM-LT cal uses EvtType >= 4, to get all COINS when
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   counting EDTM-accepted
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Richard Updates
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---------------
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10.6GeV carbon lumi scan analysis
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- Lumi #3, 5351-58 (HMS only)
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   - plots of Yscaler, Ynotrack, Ytrack
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   - get a consistent HMS current trend, ~2% increase to 65uA
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- DG: most reliable is Carbon Track, which is cleanest
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   - worries about pi- contamination at high rate in scaler-no-track
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   - Carbon Track seems flat within errors (Runs 5154-5298)
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- TH: this looks good, please move to CryoTarget study
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- GH: it would be good to check 8 or 6 GeV (whichever is more reliable) so
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     that we know things are consistent
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New script that lists the cuts applied to a given run in python anaysis
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- UTIL_KAONLT/bin/cut-check
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- used to check what cuts are used to trim the tree created by python
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  analysis
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- hopefully this will be helpful in reducing errors, as otherwise one has to
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  go through a lot of files to list all of the cuts being applied, which
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  sounds like a recipe for error
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RT, AP, AU meeting tomorrow to discuss the large right SHMS setting rate
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discrepancy between the two analyses reported last week
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Nathan Updates
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--------------
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Aerogel Calibs
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- last report: PMT4+ calib had a slope vs run#
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- broke up into 3 sections
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   - 2021-22 run now 2 parts, 1st part is most of 1st beam energy
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   - summer 2022 is 3rd part
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- takes simple mean for each period, not an error-wt average, since errors seem
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  unreliable
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- excluded some runs where NPE histo fits bad
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- put new params in hcana DBASE
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- replayed data w/new calib has better pion-separation from zeros in Aerogel
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  compared to online replay
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Still waiting on Junaid for RefTime cut check
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GHP presentation
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- hoping Tanja has scaled cross section values from Scaling Paper at x=0.311
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  otherwise he will have to read them off the plot, which is less accurate
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- will circulate draft slides next week
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Junaid Updates
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--------------
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DC Calibs
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- found some errors in PionLT.database file and kinematics file
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   - some missing run numbers and typos
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- SHMS DC look ok
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- HMS DC calibs off, still needs work
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   - getting high #events at zero bin entry
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   - DG: what kine of runs are these?  Production
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      - part of the trick is to apply electron cuts to electron arm, otherwise
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        get a lot of junk that distort the DC spectra
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      - calib code is awkward, as you have to "hard wire" the PID cuts
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   - MJ still checking things, HMS plane residuals improving
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Ali Updates
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-----------
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First look at pion-PID for high Q2 data
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- shows plots where progressively apply cuts
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- get a clean sample after HG cut, no obvious K/p leakage
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- CoinTime cut helps a lot too
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- DG: only apply the RF cut if you have to
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   - if get clean spectra w/o it, only HGC, then RF cut only gives an
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     inefficiency
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   - AU will need to look at # clean neutrons vs cut
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Vijay Updates
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-------------
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Working on pion-LT package
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- almost ready
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- debugged Fortran scripts, made changes for Summer 2019 data
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- working on cross section function for SIMC, getting some errors as GH gave
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  him an old version of the routine and some variable names have changed
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   - DG: yes, some variable names in the structures have changed, see include
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     files
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Next Meeting
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------------
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- Thur Mar 31 @ 16:00 Eastern/14:00 Regina/13:00 Pacific
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- KaonLT will go first
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