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Kaon LT Meetings » mtg_24jul11.txt

Garth Huber, 07/12/2024 07:14 PM

 
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                 Jul 11/24 PionLT/KaonLT Analysis Meeting Notes
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                 ----------------------------------------------
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                                (Notes by GH)
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                     Today: KaonLT 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, Alicia Postuma, Nathan Heinrich, Zach Sullivan, 
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   Nacer Hamdi, Muhammad Junaid, Vijay KUmar
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CSULA - Konrad Aniol
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JLab - Dave Gaskell
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FIU - Pete Markowitz
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Virginia - Richard Trotta
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CUA - Tanja Horn
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Ohio - Julie Roche
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Vijay
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-----
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Low Q2 PionLT Systematic Studies
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- SHMS acceptance cuts +/-10%
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  - delta, xptar, yptar changed together
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  - variations in L,T,LT,TT are small
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  - Dave: you should change the cut in each variable one at a time
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    - want to treat the uncertainties in each variable as uncorrelated, and
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      then add them in quadrature
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    - changing all variables simultaneously implies the 3 quantities are
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      correlated
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    - *NB* this means 6 changes in total for each spectrometer
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- changing sigLT functional form in LT-fit
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  - Exp/MC ratios at high epsilon have a pronounced cos(phi) dependence
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  - will modify functional form to see effect
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  - currently have sigLT=(A*exp(Bt)+C/t)*sin(theta*)*g(W)
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  - the C/t term was not in functions used in prior papers, will try just C as
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    a fit constant
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Richard
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-------
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High Q2 KaonLT LT-fitting
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- using sigL=(P1+P2*logQ2)*exp(P3*t), sigT=(p5*(t/Q2-1))*exp(P6*t)
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- using same sigLT equation as Vijay
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- will show only 1st iteration for all settings
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- will concentrate on lower -t region now to try to get a good fit, but will
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  need to do full t-range later for K-pole tests
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- given these caveats, initial sigL,T shown for:
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  Q2=2.115,W=2.95    Q2=3.0,W=3.14    Q2=5.5, W=3.02
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  - will look at replacing (t/Q2-1) term in sigT with (t/Q2-P7)
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- Dave: Exp/MC ratios have some weird sin(phi) dependence, implies something
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  very weird is going on, not just an interference function issue
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- Garth: suggests doing a few more iterations and plotting P1-P6 vs Q2 to see
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  what kind of Q2-depenence results
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  - *NB* then use this info as feedback for what kind of fuctional form to try
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  - Henk and GH used this approach in Fpi-1 pi-/pi+ analysis and it was useful
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Alicia
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------
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pi+ BSA analysis
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- some comments have been received on the paper.  <10% of collaboration has
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  responded
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- shows slides for Monday's presentation for comment
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Nacer
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-----
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KaonLT Heep Exp/MC ratios
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- *NB* will try modifying Heep model in SIMC to see if this helps higher beam
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  energies
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- GH will send the routine that Bill used in his thesis
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Nathan and Zach
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---------------
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PionLT Lumi Studies
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- HMS, SHMS carbon scans 16738-16746
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  - changed BCM offset by 9nA (0.025uA -> 0.034ua) and low current dependence
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    looks flatter now
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  - reduced chi-square is calculated for different fits of rel.yield versus
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    beam current
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  - adding a slope results in overfit (too small chi-square), while a flat line
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    fit gives chi-square closer to 1 (although as low as ~0.5 for some plots)
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  - *NB* conclusion is that carbon scans look good and flat.  GOOD NEWS!!
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- HMS LH2 scans 16703-16712
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  - high current point is much lower than the others, there is at least 1
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    outlier, maybe two
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  - would imply little boiling at low current, with significantly more boiling
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    at 80uA
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  - no fits to rel.yield versus beam current are good, chi-square bad for both
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    flat fit and linear drop
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  - investigating possible problems:
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    - Total Live Time (TLT) shows linear drop to 92% at 120 kHz
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    - CPULT also drops linearly, but is ~80% at low rate instead of ~100%
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  - need to recheck how CPULT is calculated, might be including DTM events
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  - Dave: you should be able to form CPULT for different trigger legs
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    - *NB* this used to be in the report files, take a look at an old version
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      of the template for the calculation
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- SHMS LH2 scans 16759-16764
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  - larger errors than the HMS scan but looks similar
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  - notably, the highest 80uA point is an outlier here too (although perhaps
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    not by as much)
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- GH: *NB* suggest to add a small quadratic term to fit versus current
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  - since both spectrometers see similar behavior, it might be real
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- Dave: target fan speed seemed to change a lot in early 12 GeV expts, makes a
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  big difference to the LH2/LD2 boiling, so that's why different early
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  experiments repot large variation in observed boiling
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  - Tanja: *NB* Josh did a study of target characteristics versus fan speed,
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    try to get a copy of his report
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- 2021 Lumi scans
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  - Zach starting to set up for doing the 2021 scans
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  - Nathan reports that the analysis script should hopefully work for 2
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    spectrometer singles runs, as it is based off Richard's original script
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  - it would be helpful to see how different the results are, partly to
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    establish the systematic uncertainty in the Lumi scans
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- Coin Lumi scans were also taken in PionLT
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  - Nathan's old code would have to be fixed for these studies
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Junaid
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------
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PionLT HeeP studies
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- results for all 9 settings shown
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  - includes offsets from Garth and Nathan's BCM calib
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  - Richard has sent new version of recon_hcana script, will check if this
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    makes any changes
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- 5.988 GeV energy Exp/MC distribution comparisons look quite good
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- 6.399 GeV Ratio<1 by about 1.5 sigma
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- 7.942 GeV Ratio=1.118
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- 8.483 GeV Ratio=1.147
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- 9.177 GeV Ratio=1.261
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- 9.884 GeV Ratio=1.156
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- 10.547 GeV Ratio=1.232
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  - clearly a systematic trend to the ratios (with some noticeable fluctuation)
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  - rechecking error calculation on the ratios
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- proton absorption correction not yet implemented to Exp yields, but this is
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  expected to make the ratios worse
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- there is an issue with 2 of the Dummy Target runs
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  - very small number of events after replay
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  - got same answer for both RH7, ALMA9 versions of hcana
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  - gets a map warning when doing replay, consulting w/ Mark Jones on this
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 Next Meeting
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- Next meet: Thur July 18 @ 15:00 Eastern/13:00 Regina
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  - PionLT will go first
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