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<p>Please find the minutes <a moz-do-not-send="true"
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_December_12,_2019#Minutes">here</a>
and below.</p>
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<h2 id="firstHeading" class="firstHeading" lang="en"><span
dir="auto">GlueX Start Counter Meeting, December 12, 2019,
</span><span class="mw-headline" id="Minutes">Minutes</span></h2>
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<p>Present:
</p>
<ul>
<li> <b> FSU: </b> Sean Dobbs</li>
<li> <b> JLab: </b> Rupesh Dotel, Mark Ito (chair),
Simon Taylor, Beni Zihlmann</li>
</ul>
<p>There is a <a rel="nofollow" class="external text"
href="https://bluejeans.com/s/SmmJI/">recording of
this meeting</a> on the BlueJeans site. Use your JLab
credentials to authenticate.
</p>
<h3><span class="mw-headline"
id="Review_of_Minutes_from_October_31">Review of
Minutes from October 31</span></h3>
<p>We went over <a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_October_31,_2019#Minutes"
title="GlueX Start Counter Meeting, October 31, 2019">the
minutes</a> without a lot of comment.
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<h3><span class="mw-headline"
id="Calibration_and_Efficiency">Calibration and
Efficiency</span></h3>
<h4><span class="mw-headline" id="Calibration_Incident">Calibration
Incident</span></h4>
<p>We discussed the issue that Sean raised at yesterday's
Production and Analysis Meeting. Calibration constants
for correction of propagation times were overwritten
about a year ago. The effects do not appear to be large,
but are visible when looking at resolution as a function
of z. Sean has yet to quantify the effect, but we know
that it is present in all of the reconstruction of 2018
data done this year.
</p>
<p>The problem was introduced inadvertently, probably
during the process of a collaborator learning how the
calibration database works. We discussed what steps
could be taken to prevent, or at least reduce the
probability, of this happening again. There is no
solution that is at the level flipping some appropriate
switch in the system. Restrictions have benefits but
also costs in implementation, management, and loss of
efficiency in making calibration changes. That said,
something will have to be done in the near future.
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<h4><span class="mw-headline"
id="Realistic_Start_Counter_Efficiency_in_mcsmear">Realistic
Start Counter Efficiency in mcsmear</span></h4>
<p>Sean brought up the issue in incorporating start
counter efficiency as a function of z into the
simulation. Mahmoud Kamel has performed studies on this
in the past. Sean suggested he could perhaps write a
short note summarizing his findings that we could use as
a guide in coding. Mark will ask Mahmoud about this.
</p>
<h3><span class="mw-headline" id="Dark_Rate_Studies">Dark
Rate Studies</span></h3>
<p>At a previous meeting Rupesh agreed to take over doing
dark rate measurements about every two weeks during the
run. As a first step Beni will write up the procedure
(or find the already-written-but-temporarily-lost
procedure) and go over it with Rupesh.
</p>
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