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Kaon LT Meetings » mtg_24apr25.txt

Garth Huber, 04/25/2024 06:50 PM

 
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                Apr 25/24 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, Nacer Hamdi, Ali Usman, Alicia Postuma, Muhammad Junaid,
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   Nathan Heinrich, Vijay Kumar
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York - Stephen Kay
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JLab - Dave Gaskell
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CSULA - Konrad Aniol
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CUA - Tanja Horn
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Vijay Kumar
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-----------
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Initial results of Low Q2 PionLT L/T-separations
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- changed formula for sigT to a+b*(-t) type form for now
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- fits now converge, was able to do several iterations
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- comparisons between Data and MC distributions look reasonably good
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  - should change lower MM cut to ~0.91, or remove entirely, to avoid
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    correction for events lost due to the cut
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- Exp/MC ratios are approximately 1, but with some phi-dependence for some
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  t-bins
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  - GH and Vijay will need to look more closely at these, with the aim of
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    making the ratios more flat vs phi
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    - likely will have to modify the sigT equation to get a better fit, need a
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      close look to see what to do
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    - possibly the LT, TT equations will also need modification
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- sig_UNS phi distributions looking better than before, the phi distribution is
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  getting more consistent between low, mid, high-epsilon
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  - these will hopefully improve further once the ratios are more flat vs phi
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- initial L/T/LT/TT cross sections
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  - sigLT has a trend to values closer to zero as -t decreases, but the
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    smallest -t bin does not have the smallest magnitude, this will need
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    investigating
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  - the t-dependence of sigL also will need confirmation, likely it will change
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    as the iterations continue
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- showing results at weekly meetings  in order to gain feedback is important,
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  we are willing to have Vijay go first for the next few meetings, if this is
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  helpful to him
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Ali
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---
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- recon_hcana was using wrong mass, gave weird phi-distributions
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  - this has now been fixed
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  - unfortunately, all SIMC needed to be re-run, as old files were deleted
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Alicia
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------
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BSA systematic uncertainties
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- A=full fit, A'=simple fit, typically A<A'
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- quoting A as final value, with syst_fit=|A-A'|
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- showing this as a +/-systematic over-estimates the uncertainty, as the real
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  value presumably is between A and A'
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- agreed that we will show syst_fit as an asymmetric error
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- will not be present next week due to other obligation, hoping to give an
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  update on the BSA paper in 2 weeks
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Nacer
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-----
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KaonLT Low Q2 PID efficiency systematics checks
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- recap of Ali's 2023 slides where HMS_cal and HMS_cer efficiencies were found
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  using Heep runs
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  - runs 6600, 6603 were from this data set
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  - used only 2-4 GeV/c runs to avoid pi- Cherenkov radiation
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  - for CAL_eff, placed tigher cuts on CER, and vice versa
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  - small rate dep was seen in CER_eff, Ali took the average, and found a
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    systematic from the RMS deviation
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Nathan
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------
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PionLT BCM calib
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- met w/Dave Mack this morning to discuss Nathan's initial results
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  - DM thinks a combined fit using runs w/same config can eventually be used
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  - suggested that Nathan look at BCM1,2 and throw away runs>50uA due to
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    small non-linearity
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  - will check how stable the parames are before doing a combined fit
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- DaveM's main concern from Nathan's Lumi work so far is that the found 170nA
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  offset is too large, was expecting an offset closer to 70nA based on prior
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  experience
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  - will recheck the offset after calibs complete
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- Nathan will write a README on the changes to the calib code after complete
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Junaid
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------
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- finding his experience @ JLab to be very valuable
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Next Meeting
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------------
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- Thur May 2 @ 15:00 Eastern/13:00 Regina
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  - PionLT will go first
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