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Kaon LT Meetings » mtg_23mar30.txt

Garth Huber, 03/30/2023 07:17 PM

 
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                 Mar 30/23 PionLT/KaonLT Analysis Meeting Notes
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                 ----------------------------------------------
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                           (Notes by GH and SJDK)
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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 - Stephen Kay, Garth Huber, Muhammad Junaid, Ali Usman, Alicia Postuma,
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   Nathan Heinrich, Vijay Kumar, Love Preet
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JLab - Dave Gaskell
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CUA - Richard Trotta, Tanja Horn
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Richard is unfortunately ill with COVID-19, and has no report
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Neither Julie nor Jacob can attend today
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Ali Updates
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-----------
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Started to look at PID other KaonLT pi+ settings
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- Central setting from Q2=2.1 high epsilon last time
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- Left and right now, as well as low epsilon settings
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- Analysing Q2 = 3.0, high and low eps now too
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Met and discussed with Richard and Alicia last Friday regarding too-high
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weirdness with right setting
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- Alicia will give update
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Alicia Updates
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--------------
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Right SHMS setting weirdness, using pi+ KaonLT data
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- initially didn't see Right setting dominate, unlike Richard, but then
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  loosened cuts and sees Right is indeed larger yield
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- Plotted only acceptance cuts, with no PID, to see right setting dominate
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   - pi+n MM cut took care of most of the yield differences, so it looks like a
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     PID cut issue
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- Good news, it's Not a replay issue, Richard and Ali's replays are consistent
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   - NH: Were plots charged normalised?
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      - No, showing raw plots
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   - RT: I checked the charges but they were about the same
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     RT also applying pid but it's pion pid vs kaon pid so something weird
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     is going on with the kaon pid for right setting
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- The right setting has issues because it's closer to the beam line, more
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  background junk
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   - VK: Is it an issue that the right has higher yield?
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      - GH: Yes, it's just garbage yield that we need to understand and clean up
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   - RT: I believe we won't be able to fix this until we do the pion background
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     subtraction because the proton peak is massive.
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      - K+ PID is more challenging than pi+ PID
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      - will need to do a pi+ subtraction before comparing L,R,C yields again
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   - GH: to avoid undue cut-dependence, it's better if K+ cuts are not so deep
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     that we have to apply a large cut-inefficiency to correct for K+ that
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     don't make the cut, in that case it's better to do a pi+ subtraction
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      - can make pi+ cuts tight to get the pi+ leakage spectrum, since we are
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        only interested in the MM distribution shape, not the absolute
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        normalization
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      - this will have to be done separately for each (t,phi) bin!
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- RT/AU will meet again once RT recovers from Covid and can talk again, will
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  discuss HGC inefficiencies and pi+ leakage spectrum for K+ PID and K+ leakage
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  spectrum for pi+ PID
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Vijay Updates
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-------------
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Switched pion routine in SIMC -> physics_iterate.f instead of physics_pion.f
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- Re-ran SIMC to simulate reaction for all settings of the Q2 = 0.38 setting
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- SHMS xptar and yptar overall look ok, edges match up quite well
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- Working on comparing other variables
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   - Want to compare Phi_pi variables bin by bin for each t-bin
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   - General agreement is good, distribution shapes seem to have better
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     agreement with data than default pion generator
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- SIMC was only arbitrarily scaled by under a factor of 2 for earlier
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  plots. Not a bad agreement at all for this point.
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- GH: Good news.  Almost ready to go back to yields then
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   - if Heep offsets determine that a beam energy offset is needed, then will
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     have to rerun SIMC, but that's not a huge problem
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- VK: Work pushed daily to GitHub. Richard/Ali can grab as needed
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- Still modifying some elements of Bill's code, primarily plotting scripts now
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   - 3 Epsilon modifications still needed
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Nathan Updates
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--------------
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Slides for GHP
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- Slide 3 TH: An image would be good here, lots of text, can grab a standard
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  sort of image
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   - GH will try to find something from an old talk by Rolf
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- Slide 5 - will make a new handbag diagram with momenta labeled
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- Slide 6 TH: A table with kinematics of the different experiments would be
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  great, Q2 ranges, etc
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   - Each cell with a different BG colour
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- Slide 7 TH: make last bullet more specific, and divide into two parts
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   a) if the factorization regime not reached, then cannot access leading twist
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      GPDs in these experiments
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   b) if sigT large, then opens the possibiity of accessing Transversity GPDs
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- DG liked the log y-scale versions of the plots, as otherwise high Q2 points
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   get buried along x-axis
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- Slide 8 - Nathan concerned whether some statements are a bit controversial
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   - GH: expect point-like behavior for mesons with heavy quarks, pion is
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     relatively large meson in comparison, means heavy quark mesons should
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     factorize at lower Q2 than pions
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   - TH: Check some of Christian Weiss' presentations for more information on this
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- TH suggests a rephrasing to improve emphasis of slide
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  - if we want to establish factorization globally, need to look at multiple
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    DEMP reactions
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  - various other experiments have Vector Meson data, can get quasi-L/T
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    separation via s-channel helicity conservation on decay products
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  - need to also investigate the pseudoscalar mesons, in this case Hall C is
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    the only way to get L/T-separated data
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   - Rho/VM data?
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      - GH: HERA has a lot of VM data, in addition to Hall B
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- Slide 9 - Could be made more positive than the word "inconclusive"
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   - TH: DVMP Paper - https://inspirehep.net/literature/1404915. It includes
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     both vector and pseudoscalar meson data
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   - the previous work was not a dedicated measurement, exploratory
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   - this is the FIRST dedicated study
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- Slide 11 - Make clear the L/T-separation requires different beam energies,
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  which are taken at different rates
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- Slide 12 - Remove map of Virginia and make a table of beam energies/gradients
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  used
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- Importance of phi coverage could go earlier? Right after spectrometers?
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   - Need to think about ordering of various slides here a lot
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   - GH: suggest to move SHMS+HMS slide earlier, leaving other Hall C
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     instrumentation slides where they are
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   - then can include the 3 SHMS setting slide to after L/T-sep
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- Slide 17 - Clarify this is coincidence between two spectrometers
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   - add CoinTime equation
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   - needs to be understandable by those not familiar with Hall C
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- Slide 18 - Date of expected results?
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- Slide 19 - will change to log-y plots
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   - need to clearly indicate that y-positions of projected data are arbitrary,
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     and that the projected errors are estimated (based on obtained statistics)
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- Slide 20 - Match colour of labels to colour of text in table
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- Slide 21 - change "upper bound" to whatever wording is decided on earlier slide
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- On thank you slide, include DoE/CUA grants
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   - Get Julie's grant # etc too
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- Nathan - Dry run April 5th, Wednesday
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   - Will set up on Zoom so remote people can join - 15:00 Eastern (13:00 Regina)
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   - Regina participants are expected to attend in person, LB 235 
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   https://uregina-ca.zoom.us/j/98764326984?pwd=TVg0Uk9CY0RxL2ZSZCsxYVZCZ29oUT09
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   Meeting ID: 987 6432 6984
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   Passcode: 259164
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Next Meeting
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------------
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- Thur Apr 6 @ 16:00 Eastern/14:00 Regina/13:00 Pacific
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- PionLT will go first
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