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<u><b>Hoyoung(From Sept 28):</b></u> Taking closer look at runs that
have been giving suspiciously low packing fractions. These are
perpendicular 4.7GeV runs. Adjusting the HMS MC to use the exact same
beam energy/position and HMS momentum setting improved agreement
between data and MC, but the packing fraction only increased by ~1%. <br>
Will look at one of these suspect runs (72828) in 2 halves to see if we
can find something onsetting. <br>
Asking MCC to check their archiver for any happenings during this part
of the data taking (helicity status, IOC trips, ...)<br>
Oscar suggested for Hoyoung to look at the HMS asymmetries to see how
these compare with the those from BETA.<br>
<a class="moz-txt-link-freetext" href="https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Hykang#2010.2F09.2F20">https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Hykang#2010.2F09.2F20</a><br>
<br>
<br>
<u><b>Hovhannes:</b></u> Looking at positron contribution. Looking at
deltaX(hit in Tracker - straight-track hit) for some reconstructed
energy bins. In the plots, the blue curves represent electrons,
pink=>positrons, and yellow=>accidentals/background. The deltaX
not being centered at 0 might be from shifting of the Tracker itself.
Sees that contribution decreases exponentially as energy increases.
Requiring 2 clusters, which is part of good event ID, already decreases
the pair symmetric background some initially. <br>
Will look at this as a function of polar angle (theta) with fixed
energy and check using the GEANT to see what is expected.<br>
<a class="moz-txt-link-freetext" href="https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Positron_contribution">https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Positron_contribution</a><br>
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<u><b>Jon:</b></u> Looking at BigCal energy resolution. Used a process
found in a NIM article(cited in link) looking at decaying pi0-> 2
photons, fixing the energy of one cluster and varying the energy of the
other cluster. These clusters were mostly in the RCS part of BigCal.
Used 6 Carbon runs for this study. Including the low energy
(E'<0.5GeV) causes some bias because the NN doesn't work at that
range. <br>
<a class="moz-txt-link-freetext" href="https://hallcweb.jlab.org/experiments/sane/wiki/index.php/JrmEResolution">https://hallcweb.jlab.org/experiments/sane/wiki/index.php/JrmEResolution</a><br>
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<u><b>James:</b></u> Looking some more at swimming hits from BigCal to
the Tracker using the integrated Bdl method. Using the perpendicular
data for this. This is a work in progress.
<a class="moz-txt-link-freetext" href="https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Particle_Tracking_to_Front_Tracker%2C_Target#Tracking_to_Target_with_Bdl:_9.2F29.2F2010">https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Particle_Tracking_to_Front_Tracker%2C_Target#Tracking_to_Target_with_Bdl:_9.2F29.2F2010</a><br>
Updated perpendicular asymmetries, using different Q2 and W bins. It
seems that the perpendicular data has 1/3 the events seen in the
parallel data. Will try using geometrical cuts to see if there is some
part(s) of BigCal with lower efficiencies. <br>
<a class="moz-txt-link-freetext" href="https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Raw_Asymmetries#Updated_plots.2C_Multithreaded_Analysis:_9.2F29.2F2010">https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Raw_Asymmetries#Updated_plots.2C_Multithreaded_Analysis:_9.2F29.2F2010</a><br>
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<u><b>Anusha:</b></u> Comparing data with MC for NH3 runs. This is
specifically using the HMS, using Eric Christie's MC. Does not see
hardly any elastic events in the MC. Is working on finer momentum
binning to see if some come out with the radiative corrections. <br>
<a class="moz-txt-link-freetext" href="https://hallcweb.jlab.org/experiments/sane/wiki/index.php/MC_with_NH3">https://hallcweb.jlab.org/experiments/sane/wiki/index.php/MC_with_NH3</a><br>
<br>
<br>
As always, please let me know if I missed anything or if I made any
mistake(s).<br>
<br>
Next meeting will be October 7th at 15:30.<br>
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