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Kaon LT Meetings » mtg_26jan29-30.txt

Richard Trotta, 02/06/2026 12:10 PM

 
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January 29th, 2026
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Today: KaonLT will be discussed first
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Present
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---
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Regina - Muhammad Junaid, Alicia Postum
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CUA - Sameer Jain, Chi Kin Tam
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Virginia - Richard Trotta
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Jlab- Dave Gaskell
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FIU - Pete Markowitz
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---
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Sameer
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- Updated coincidence time plots were shown with new window cuts (~30 to 105 ns)
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	- Automated procedure was use which showed consistent  results from the "by-hand" approach
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	- Nathan suggested showing coinblock vs S1X which look as expected (decreasing efficiency as SHMS angle decreases)
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	- Sameer wants to do a comparison of two approaches between using ptrig scaler vs event types but got odd results
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		- It was pointed out by Dave and Richard that this isn't a good comparison as it is just looking at computer livetime rather than coinblocking
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- Sameer and Nathan need to meet to iron out these updated results
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- Once Nathan can reproduce Sameer's results, he can finish up the rest of the settings
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Junaid
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- No updates, but working on systematics and slides for upcoming talk (WNPP)
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Alicia
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- phi-007 experiment ERR has been tentatively scheduled for Weds Feb 18
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- One of the questions in the charge is whether the simulated missing mass resolution presented in the proposal is supported by the collaboration's previous experience with similar HMS+SHMS setups
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- Henry approached Alicia to give a talk about the u-channel KaonLT analysis, comparing our resolution to that expected for the phi-experiment 
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- We do not have visible phi contributions, but can compare the omega peak
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---
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January 30th, 2026
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Today: PionLT will be discussed first
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Present
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---
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Regina - Muhammad Junaid, Alicia Postum, Vijay Kumar, Nathan Heinrich, Nermin Sadoun
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CUA - Sameer Jain, Chi Kin Tam
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Virginia - Richard Trotta
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Jlab - Dave Gaskell
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York - Stephen Kay
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FIU - Pete Markowitz
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---
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Nacer
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- Verbal update
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	- Kaon absorption factor (discussed in Hall C Winter meeting) was included now
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	- Just waiting on low Q2 cointime blocking from Sameer
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	- Rebinning t-bins
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	- Preparing poster for Canadian conference (WNPP)
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Vijay 
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- Systematic uncertainty
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	- 2 iterations, vary cuts by +/- 10% and look at the cross section difference
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	- Standard Cuts: MM, PID, CT
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		- But Dave said the CT cut should stay the same and not vary
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		- Dave believes it wasn't done in the past, perhaps a good discussion when everyone is here
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		- Efficiency would also need to be included since you know you'll be missing events
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	- Standard deviation within +/-5%
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		- Outlier bins are due to poor statistics
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	- Next step: t-correlated systematics
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Kin+Richard
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- Trying to isolate an inconsistency between their results
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	- Kin can reproduce Richard's results using Richard's parameters+functions, but the reverse isn't true
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	- Richard has been using the form (W^2-M^2)^[0.85W^2-5.97W+12.68] while Chi Kin uses the traditional (W^2-M^2)^2
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		- This discrepancy in the Wfactor seems to be the main culprit so they are trying to track down where this discrepancy arises in Richard's code
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Nermin
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- CT offset determined using Gaussian fit
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- Random CT subtraction 
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	- +/- 2-22 ns
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	- Fixed width of 4 ns
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	- 10 random windows used (5 and 5 on each side of peak)
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- PID cuts are being improved
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	- new cuts with small improvements
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	- Dave said the plots (which include PID+CT) shown look like an RF is not necessary, things are clean as is and it is only adding additional correction
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- Next step: Look at which PID cuts to keep and remove 
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	- Cherenkov, for instance, may be better to remove while keeping RF
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Alicia
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- Pythia updates
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	- Q2=3.0, W=3.14
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		- (S)HMS: A bit of over-subtraction in the center of the acceptance with the focal plane variables
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			- This issue isn't effecting phi though 
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		- The main issue is an offset that seems to exist, which may be from an error in the SIMC input file
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			- Going to check locally with the Regina group
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		- Make sure the correct events are being ran before another big Pythia run
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	- Q2=3.0, W=2.32
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		- In addition to the above offset, a few odd dips in Q2, W, etc with the background pythia cuts that need to be resolved
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			- This is a consistently tough setting
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	- The more general issue (likely with the SIMC input file) needs to be resolved before moving on
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		- Next step: Comparing with pion input files to double check no typos or issues
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Nathan
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- No updates due to upcoming WNPP, but need to double check with Sameer about consistency with results. Once he is able to match Sameer's results they can move in their own directions.
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