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Kaon LT Meetings » mtg_23dec14.txt

Garth Huber, 12/14/2023 08:20 PM

 
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                 Dec 14/23 PionLT/KaonLT Analysis Meeting Notes
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                 ----------------------------------------------
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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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-------
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Regina - Garth Huber, Muhammad Junaid, Nathan Heinrich, Ali Usman,
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   Vijay Kumar, Alicia Postuma, Nacer Hamdi
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CUA - Richard Trotta, Tanja Horn
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JLab - Dave Gaskell
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FIU - Pete Markowitz
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Nathan
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------
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Getting ready for full replay of PionLT data
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- param files in standard.database are set up
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  - modifications to param files done by some scripts, took several days to get
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    everything working
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- CoinTime offset needs adjustment due to RefTime cut change
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  - wrote a sript to plot CoinTIme, want it centered around 0 w/ new offset
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  - replays to determine new CT offset worked
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    ~30 runs done so far, more planned
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  - PTRIG6 runs will require different CT offsets than PTRIG5 runs
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- full replay going soon
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Junaid
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------
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More on getting ready for full replay of PionLT data
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- updated def cuts for efficiency studies, report files
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- setting up batch scripts before starting full replay
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Richard
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-------
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Batch job information
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- recommends to separate hcana replay from python script job
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  - makes memory allocation for jobs easier
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  - need to increase memory efficiency for batch jobs in order to get a good
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    running priority
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  - 800MB seems to be a good allocation for hcana replays
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  - python request needs 10GB, seems large, needed for jobs to run properly
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  - GH: try creating a python binary for production running, interpreted python
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    is good for development, but is inefficient for large scale running, this
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    should reduce memory usage and CPU time
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- newest replays at:
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  /lustre19/expphy/cache/hallc/kaonlt/Pass3_Dec_2023
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- rough vresion of script that calculates resource usage:
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  /u/group/c-kaonlt/USER/trottr/lt-analysis/usage_check.sh
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- meeting w/ Ali to discuss efficiecies, uncertainties in effs, Heep yields
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- Ali mentions that we also need to implement offsets into SIMC physics input
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  files
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Ali
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---
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pi+ Delta0 BSA analysis
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- starting w/ Q2=2.115, 3.0-2.32, 3.0-3.14 settings
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- MM study in Delta region
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  - need bin-by-bin shape study
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  - SIDIS scaled to data in MM=1.4-1.55 GeV region
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  - pi+n MC scaled to neutron peak
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  - Delta MC is matched to data after n, SIDIS are subtracted
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  - Delta yields calculated for MM=1.1-1.4 GeV region for each helicity setting
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  - BSA calc separately for Delta, Bkd, Sum Yields
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- maybe we can do 2 t-bins for 2 FF points (higher statistics) after adding
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  Left, Center, Right SHMS settings
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Things to be done:
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- check rho contribution to this MM region
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- implement kinematic offsets in analysis
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- understand pi+n resolution difference
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Dave: it's important to confirm you're doing a Dummy target subtraction
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- surprised the piDelta BSA is so close to the BSA asymmetry, is there a good
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  physics reason why they're so similar?
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- it would be helpful to calculate also the BSA for the 1.35<MM<1.55 region, to
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  see if the BSA is different there or not
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Discussion on the pi+n resolution difference:
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GH: the HMS drift chamber resolution in SIMC is set in:
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  hms/mc_hms_hut.f
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  variable: hdc_sigma is set to 0.030 for each plane
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  - similarly for SHMS in shms/mc_shms_hut.f
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  DG: first need to look at correlations between FP variables and MM before
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  making adjustments
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  - Alicia had done an intial look at this, but wasn't completed.  Will look in
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    more detail after the holidays
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Dave: also need to confirm whether NGC is in shms_hut.f or NOT
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- want it OUT for KaonLT, IN for PionLT
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- it would be great if Dave could add an input flag which would set this,
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  otherwise, we will need different versions of the code for KaonLT, PionLT
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Dave: Maybe the beam energy spread is the issue?  PROBABLY!
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- in 6 GeV era, the beam energy spread was never an issue
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- but it's significantly worse for 10 GeV beam!
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- Note that this refers to the width of the beam energy distribution, and is a
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  different parameter than the uncertainty in the beam energy (which refers to
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  the uncertainty in the centroid in the distribution), not the width
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  - For an accurate simulation, SIMC does not use a monochromatic beam energy,
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    but rather has a Gaussian energy distribution given by this width
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- DG finds a 2013 Note: at 11 GeV the spread is 0.02%, at 6 GeV 0.01%.  No
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  mention of what it is at 8.5 GeV
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  - GH will write Jay Benesch to get more info
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Alicia
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------
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Reprocessing 10.6GeV data with offsets
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- will look at memory issue mentioned by Richard for batch jobs
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- next step will be MM study, binned in t
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Nacer
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-----
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Calibration checks of 3.835, 4.933 GeV KaonLT data
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- SHMS beta distribution was around 1.1, with new Hodo time walk parameter
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  (determined from 3.8 data) beta is now closer to 1
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  - good news, this time walk param also works well on 4.9 data
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- next step is to check if this makes any effect on DC calib
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- Ali: new offsets should be automatically implemented in his analysis, if he's
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  pointing to the right files
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  - NH should confirm with AU this is the case
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Vijay
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-----
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Lumi and Heep cross section check for Summer 2019 data
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- using Richard's method for Lumi
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- results: Carbon -0.243%/100uA   LH2 -5.06%/100uA
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  - consistent with Richard's results, which is good
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- Heep MC/Data yields are also consistent with 1, within errors
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Dave: the plots look a bit weird in that the error bars for many points are
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  quite large (+/-5%)
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  - Pete: judging from the small scatter of the data, it looks like the error
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    bars are over-estimated
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  - Ali: we had originally over-estimated the tracking efficiency
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    uncertainties, maybe that's an issue?
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  - Garth: or maybe it's simply an error in the plotting script?
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  - either way, this needs to be rechecked, as the uncertainties on the Lumi
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    and Heep checks are very important!
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- another issue to check: it's very important to confirm that an error-weighted
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  fit of the results is done
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- the results are very encouraging, but some checks are still needed
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Next Meeting
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------------
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- Thur Dec 21 @ 15:00 Eastern/14:00 Regina
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  - KaonLT will go first
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- there will be no meeting on Dec 28
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- our first meeting of 2024 will be on Thur Jan 4
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- after that, we will have to see what people's schedules are for the new
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  semester and see if this time still works for everyone, or not
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