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Kaon LT Meetings » mtg_23may11.txt

Garth Huber, 05/12/2023 03:35 PM

 
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Richard:
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Met with Carlos to discuss luminosity scan analysis differences.
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Found Carlos was looking at ELREAL while Richard was looking at ELCEAN.
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Results more consistent when both using ELREAL. 
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Showed luminosity scan fits with error bars, but something still looks not
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quite right. Will use root next (using python right now) to see if fit
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parameters/uncertainties look more reasonable.
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Discussed next replay for 2018/2019 data - after offsets determined.
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Ali:
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Grabbed latest BPM calibration info from wiki:
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https://hallcweb.jlab.org/wiki/index.php/BPM_calibration_information
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Had some impact on peak positions, but not large.
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BPM calibrations: will use Feb. 2019 values since data were taken in March.
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For all Fall 2018 data, will use 8/29/2018 values.
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Showed raster-y tests (changing sign) - we had it right to start with.  Small
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residual dependence on raster-y could be taken out by scaling the value of
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raster-y.  This could have impact on other resonstructed quantities though
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(xptar, ztar) so we should be cautious about doing this.
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DG note: perhaps we could just scale the relevant xtar-delta matrix element?
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Vijay:
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Question: Will raster-y issue be addressed before next replay? Yes - it should
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be.
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HMS calorimeter efficiency: getting rather low efficiency using production data
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(0.95). Cherenkov cut is pretty low though (0.65 npe).  Will re-do with
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higher cut. Also will look at Heep data.
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Nathan:
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HMS Cherenkov calibration: fixed main issue from last week - was selecting wrong
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timing peak.  Now calibrations look reasonable - but, more random variation than
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one would like.  Julie suggests looking at 2 runs that have very different
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calibration but were taken close together in time. Also, the fit range for
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the single-photo electron peak might be too big.
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Junaid:
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HMS DC calibration.  Added multiplicity cut and drift distance spectra look
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good now (residuals also look good, but I think they were fine before).
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DC calibrations will be done for each HMS (Q2,W, epsilon) setting.
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SHMS is next.
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Question at end of meeting from Ali: After determining offsets from Heep data,
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should they ne included in simc?  Yes - they represent real changes to the
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spectrometer central angles and momenta which could impact average Q2, W, -t
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etc.
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