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May 2/24 PionLT/KaonLT Analysis Meeting Notes

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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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Regina  Garth Huber, Nathan Heinrich, Nacer Hamdi, Ali Usman, Muhammad Junaid,

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Vijay Kumar, Zach Sullivan

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CUA  Casey Morean, Tanja Horn

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JLab  Dave Gaskell

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CSULA  Konrad Aniol

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York  Stephen Kay

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UVa  Richard Trotta

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FIU  Pete Markowitz

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Nathan

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BCM calib results for PionLT

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 Dave Mack impressed with Nathan's fast progress

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 DM loked at NH's 2021 results, calculated some numbers to use

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 NH looked at 2022 results, calculating his own numbers to show DM

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 BCM4A 202122 data

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 DM, NH get similar calibration constants

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 BCM2 looks good, DM & NH numbers almost identical

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 NH shows fit of BCM Rate vs Unser Current and Residuals

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 Time vs Residual plot uses time of BCM runs themselves, to check for time

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dependence in fit residuals

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 residuals vs time look pretty stable, which is good news

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 the residuals plot that is concerning is BCM4A, 2021 data

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 shows a small (23 sigma) trend in residual with time

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 two BCM calib for runs 1250012900 very consistent, so also are two BCM

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calib for runs 1370014100, but a noticeable change between these two sets

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 no obvious reason why these 2 sets are different, or even where to put a

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time break between them

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 pushed calib param to HallC_replay

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 BCM4A uses error weighted average of these 4 2021 points

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 also takes weighted average of 4 2022 points

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 obvious break between these two sets is the end of 2021/start of 2022

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running

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 Conclusion:

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1) can use BCM2 or BCM4A, they have similar saturation @ high current

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 DM adds a quadratic term above 50uA

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 DG: Nathan should use the quadratic correction already in hcana, it was

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determined with a current source and should be still valid

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 Nathan will apply DM's quadratic correction and see if it works

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 after this, Nathan will replay all Lumi data

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2) Nathan has not calibrated BCM4B

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 2022 gain is very large, saturates at high current, but it might be very

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useful for low current LD2 data

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 this will be left for a future student looking at LD2 data, we need to be

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sure to leave an obvious note so this is not forgotten!

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3) BCM4C should not be used at all

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 less stable than BCM4A and similar gain

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 everything seems sensible so far, we look forward to seeing the Lumi results

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after the replay, to confirm the calibration and nonlinear correction

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Junaid

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PionLT Heep OOP offset results

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 followed Garth's method for KaonLT data

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 get similar offsets

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 phi_HMS=+2.28mr, phi_SHMS=0.41mr

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 error bars seem very small, and this could affect the fitting results

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 GH needs to review his notes and let Junaid know what errors to use

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 GH gave Junaid a set of inplane Heep offfsets, not yet implemented

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Vijay

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Low Q2 PionLT L/Tseparations

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 changed MM lower cut from 0.93 to 0.91, as per last week's feedback

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 showed cointime for all 3 epsilon, and diamond cuts

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 did 15 iterations since last week

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 cross sections are stable now, which is good, but there are some anomalies

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in the phidistributions and Data/MC ratios

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 most likely, the fitting function needs to be adjusted to get a better fit

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 e.g. sigT is just a simple linear dependence in t right now

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 Garth and Vijay need to discuss this early next week

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Richard

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KaonLT L/Tseparations

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 concentrating now on Q2=3, W=3.14 data, after it's working better will move

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next to high stats Q2=2.1 setting, and the lower statistics high Q2 settings

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will be last

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 tried customizing tbinning a bit more

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 observes a significant Q2shift with tbin, and this influences the

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parameterization

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 still using previous equation for t_ave=0.1112+0.0066*log(Q2) used in sigT,

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will need to revise this for KaonLT kinematics

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 GH thinks that the function for sigT is too complcated, should try a simpler

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function, as Vijay has done

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 Richard is giving a talk on Meson Structure @ EIC in Nanjing, May 1417

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 25+10 min talk

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 has old slides to use

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 needs to circulate a draft soon

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Ali

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piDelta BSA analysis

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 looking at MM fits again after fixing recon_hcana to use m_pi instead of m_p

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 Q2=5.5 will have one tbin, t<1.05, excluding 1.051.60 region

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 gets reasonable phi coverage now

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 varied tcut and then looked at MM distribution, to see what tcut to use

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 Center setting: all 8 phibins are filled

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 shape study fits generally consistent w/shape of data

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 data have some fluctuations (statistics?) and the MC smoothly goes

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through the trend

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 Right setting: data fill 4 phibins, 2 have lower statistics, but MM fit

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still does a reasonable job

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 Left setting: data fill the other 4 phibins, 2 with low statistics

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 fit fails for the 2 low stats phi bins also because MM range is limited

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 however, these bins are filled w/center data, so overall will be OK

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 will redo shape study for other (Q2,W) kinematics

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 Garth: the SIMC resolution tuning was done when recon_hcana had wrong mass

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 did you rerun your scripts to check that things are OK?

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 yes, checked that MC did not overestimate tail for any tphi bin

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Nacer

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Low Q2 KaonLT analysis

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 looked at Lumi scripts written by Richard

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 had to do some path tweaks to get them to work in his account

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 Richard will point Nacer to special Lumi runs done later by Mark Jones &

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Peter Bosted @ 10.6 GeV

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 this exercise is mostly for Nacer's overall understanding, next step would

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be to look more closely at the Heep data taken with 3.8, 4.9 GeV beam

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Hall A/C Summer Workshop discussion

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 it seems they are looking for talks about "publication ready" results

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 Richard, Vijay, Ali results not yet at this stage, maybe January workshop

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would be better

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 Alicia has done further BSA work since January update, and plots she shows

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should be the same ones as in the paper

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 Tanja will reply

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 workshop is July 1516

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Next Meeting

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 Thur May 9 @ 15:00 Eastern/13:00 Regina

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 KaonLT will go first

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