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<p>Colleagues,</p>
<p>Please find the minutes below and at</p>
<p>
<a class="moz-txt-link-freetext" href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_February_8,_2018#Minutes">https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_February_8,_2018#Minutes</a></p>
<p> -- Mark</p>
<p>___________________</p>
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<h2 id="firstHeading" class="firstHeading" lang="en"><span
dir="auto">GlueX Start Counter Meeting, February 8, 2018,
</span><span class="mw-headline" id="Minutes">Minutes</span></h2>
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lang="en">
<p>Present:
</p>
<ul>
<li> <b> FIU </b>: Mahmoud Kamel</li>
<li> <b> JLab </b>: Thomas Britton, Mark Ito (chair),
Simon Taylor</li>
</ul>
<p>There is a <a rel="nofollow" class="external text"
href="https://bluejeans.com/s/5UQID/%E2%80%8E">recording
of this meeting</a> on the <a rel="nofollow"
class="external text"
href="https://jlab.bluejeans.com/">BlueJeans site</a>.
Use your JLab credentials to authenticate.
</p>
<h3><span class="mw-headline"
id="Review_minutes_from_the_meeting_on_January_11">Review
minutes from the meeting on January 11</span></h3>
<p>We went over <a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_January_11,_2018#Minutes"
title="GlueX Start Counter Meeting, January 11, 2018">the
minutes</a> without significant comment.
</p>
<h3><span class="mw-headline"
id="Calibration_and_Efficiency">Calibration and
Efficiency</span></h3>
<p>Mahmoud showed slides on his <a rel="nofollow"
class="external text"
href="https://halldweb.jlab.org/talks/2018/SC_Meeting_02_08_2018.pdf">recent
work analyzing 2018 data</a>. Please see the slides
for plots and details.
</p>
<ul>
<li> In general, calibration constants are close to
those obtained for Spring 2017.</li>
<li> Propagation time evaluation plots were shown, using
the old constants. Results in all sections (nose,
bend, and straight) are flat, but an offset from zero
is visible.</li>
<li> Overall time resolution is a bit worse than he has
seen before; 314 ps now vs. 280 ps before.</li>
<li> Overall efficiency for 2018 data comes out at 97%.</li>
<li> For efficiency from simulated data he gets 99%,</li>
<li> Interestingly, the treads in variations in
efficiency sector-to-sector seem to match between data
and Monte Carlo. Likely Simon did a good job in
characterizing the non-ideal geometry of the start
counter.</li>
</ul>
<h3><span class="mw-headline" id="NIM.2FTDR">NIM/TDR</span></h3>
<p>The NIM paper is still out for comment from the
Collaboration. So far only two collaborators have
offered suggestions (thanks Simon and Sascha Somov).
Collaborators are encouraged to read it and comment. The
paper can be found <a rel="nofollow" class="external
text"
href="https://halldweb.jlab.org/DocDB/0034/003497/001/st_nim_article.pdf">here</a>.
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