Feb 9/23 PionLT/KaonLT Analysis Meeting Notes --------------------------------------------- (Notes by GH and SJDK) Today: PionLT will be discussed first Please remember to post your slides at: https://redmine.jlab.org/projects/kltexp/wiki/Kaon_LT_Meetings Present ------- Regina - Stephen Kay, Ali Usman, Alicia Postuma, Nathan Heinrich, Garth Huber, Vijay Kumar, Muhammad Junaid, Love Preet JLab - Dave Gaskell CSULA - Konrad Aniol CUA - Tanja Horn, Richard Trotta Nathan Updates -------------- Result of detector time and reference time cut analysis - Q2 = 3.85, W = 2.62, Left, Low eps (LH2+), whole setting - With new cuts, fine ~200 more pions compared to online - ~2.5% more events (8261 vs 8070) - Distributons look slightly better, very subtle changes - DG - Probably worth checking a setting with a poor real/random ratio - May see a more dramatic difference - Try a pi- run - Nathan has it, but no online plots for comparison - Q2 = 3.85, W= 2.62, low eps, left - https://logbooks.jlab.org/files/2022/09/4039344/Q3p85W2p62left_lowe_LD-_Pion_Analysis_Distributions.pdf - 4806 pions - Looks like we have less now - Could be that some runs were missed (setting was split in two) - Please do a more thorough comparison for a pi- run - REMEMBER: All data are guilty until proven innocent! - Pushed changes to param files, std.kin - not everything is replayed yet - ref time cuts stable so this part should be okay now - Next step is Cherenkov calibs Junaid Updates -------------- Back from Pakistan - Trying to catch up on classes/get back on track with analysis - DC and calorimeter calibration is next step Richard Updates --------------- Changes to PM/EM calcs in SIMC - For SIMC/hcana comparison, complicated doing it in SIMC - Use a script to convert root file - Made this and ran it - Nothing looks different? - New variables look the same as the old ones - DG - Seems very strange - RT will meet with DG tomorrow about this Weird Right setting from last week - tightened up CoinTime cuts - CT peaks slightly offset, will correct for at some point - Dramatically imrpoved MM distributions - Black is right, green centre, red left - Black looks much improved - Still a bit high, but now only by ~50% instead of 10x - -t distribution no longer going through 0 - SK - Thought, we never plot 2D t vs anything other than phi - Could be interesting to check and remove junk events - t vs CT/RF? - For black (right) CT dist, tails are being removed - real events removed - GH - Do we need to correct for this? Cutting real events? - DG - Is this a final cut or just a diagnostic? - In principle, spectra should look the same with tight cut or with random subtraction, not the same indicates a problem that needs to be investigated e.g. if peaks left/right of real peak are actual physics events from other process - Still need to optimize PID cuts - only temporary cuts - will have to investigate where e-pi, e-p coins are compared to e-K and adjust cuts accordingly - Maybe cuts not being applied correctly for right setting? - Something is clearly dramatically different for the right setting - GH: Right setting probably has high SHMS rates, at very forward angle Please *look up* running conditions of right setting comp to cent, left Ali Updates ----------- HMS Cherenkov and calorimeter efficiency study - slide nicely lists ALL cuts applied - Wide range of kinematics investigated in KaonLT data - Run 4871: - Cherenkov efficiency is very low (94.82%) - Cal eff=98.66% - Run 4919: - Cher eff=93.96% - Calorimeter efficiency v.low (90.75%) - A lot of pi- contamination present, not a good setting for efficiency study - Run 4987: - Cherenkov efficiency ~97.15% - Cal 98.93% - Calorimeter a little low? - Run 5222: - Cherenkov 96.16%, calorimeter 99.18% - DG: this looks like a classic case of FADC-DT effect due to HMS-Cer light leak This is a *real effect* that will have to be included in efficiency The complication is that this FADC-DT is in priciple rate dependent and it may be tricky to separate out the rate dependence from other inefficient effects - Looks like we have a light leak in the Autumn 2018 data - Could've been introduced when the HMS mirror was fixed - Will be there for *all* KaonLT data and Summer 2019 PionLT data, so Vijay needs to be careful about this in low Q2 analysis as well Spring 2019 data efficiencies - Run 7909: - 75.71% Cherenkov efficiency, 96.98% calorimeter efficiency - Low total efficiency in low epsilon data - it's all the pions! - Run 7979: - Cer 94.92%, cal 99.09% - Calorimeter efficiency is pretty good - DG: I would expect a cal eff closer to 99.5% - AU: will try applying a neutron MM cut to further clean the sample, expecting a further increase of 0.5%, i.e. closer to what DG expects - Run 8255: - Cer 71.66%, Cal 95.58% - low stats in a single run, this is high Q2 low epsilon - need to add more runs to get better #events - DG - Suggest to Look at HeeP singles to get a handle on these efficiencies - Cut tightly on W2 dist, eliminate pions - Should have a nice clean sample - GH - Hopefully singles fill more of the focal plane than HeepCoin - Most of the physics settings it's hard to get a usable efficiency number due to pi- contamination in HMS - GH - Focus on 1-2 settings that look promising, otherwise, focus on the HeeP - Don't do a run by run efficiency, just use result from HeeP to guide this Vijay Updates ------------- Analysing Summer 2019 Q2=0.38 data with 3 epsilon settings - fixed issue with cut file, weird random peak to left of prompt peak is gone - Can probably take a lot more peaks on each side of the prompt peak for random subtraction - At least 2 more on each side - Diamond cut implemented, needs some small adjustment on top edge in comparison to low epsilon data - Still finalising t-binning - ~ 45k events per bin (summed over all SHMS angles and epsilon) - 8 t bins - GH for first t bin, should move left edge of the bin closer to the data - For low Q2 FF test, the dependence at low -t is crucial - Should go very narrow on binning at low -t - Could go up to 10 bins - DG - What is the -t resolution? - Can't bin finer than this or t0bin migration will be a big issue - GH will discuss with VK how to get this info from SIMC Alicia Updates -------------- - Assignments/presentation updates - No new updates, will have something after WNPPC Next Meeting ------------ Thur Feb 16 @ 17:00 Eastern/16:00 Regina/15:00 Mtn/14:00 Pacific - KaonLT will go first - SK, NH, GH, AP, LP will connect from our hotel room in Banff - GH, AP, LP might be a bit late