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<p>Folks,</p>
<p>Please find the minutes <a moz-do-not-send="true" href="https://halldweb.jlab.org/wiki/index.php/HDGeant4_Meeting,_November_29,_2021#Minutes">here</a>
and below,</p>
<p> -- Mark</p>
<p> _________________________________</p>
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<h2 id="firstHeading" class="firstHeading" lang="en"><span dir="auto">HDGeant4 Meeting, November 29, 2021, </span><span class="mw-headline" id="Minutes">Minutes</span></h2>
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<p>Present: Alex Austregesilo, Sean Dobbs, Mark Ito
(chair), Igal Jaegle, Richard Jones, Simon Taylor, Beni
Zihlmann
</p>
<p>There is a <a rel="nofollow" class="external text" href="https://bluejeans.com/s/pgAzBpDI2iH">recording
of this meeting</a> on the BlueJeans site. Log into
the <a rel="nofollow" class="external text" href="https://jlab.bluejeans.com">BlueJeans site</a>
first to gain access (use your JLab credentials).
</p>
<h3><span class="mw-headline" id="Announcement">Announcement</span></h3>
<p>There will be a <a rel="nofollow" class="external
text" href="https://mailman.jlab.org/pipermail/halld-offline/2021-November/008696.html">meeting
at 4 pm tomorrow</a> to discuss preparations for the
upcoming Computing Review.
</p>
<h3><span class="mw-headline" id="Review_of_minutes_from_the_last_meeting">Review of
minutes from the last meeting</span></h3>
<p>We went over the <a href="https://halldweb.jlab.org/wiki/index.php/HDGeant4_Meeting,_November_15,_2021#Minutes" title="HDGeant4 Meeting, November 15, 2021">minutes
from the meeting on November 15</a>. Richard repeated
his report of a possible issue where timing signals from
the FCAL do not agree between data and MC. There was a
report of seeing accidental peaks in the raw timing
histograms in simulation where in data they do not
appear. Richard explained that In data, one needs to
subtract the RF to get peaks; in simulation, if one does
the same thing, the seen-in-raw-hits peaks persist. By
doing time difference to time-difference comparisons,
there is no mystery, and these are the only comparisons
we should be doing anyway. He is waiting for
confirmation of this understanding from the folks who
raised the issue.
</p>
<h3><span class="mw-headline" id="Issues_on_GitHub"><span class="external text">Issues on GitHub</span></span></h3>
<p>We looked at the <a rel="nofollow" class="external
text" href="https://github.com/JeffersonLab/HDGeant4/issues">Issues</a>.
</p>
<ul>
<li> <a rel="nofollow" class="external text" href="https://github.com/JeffersonLab/HDGeant4/issues/196">Data/MC
discrepancy in FCal Matching around Beam Hole</a>
<ul>
<li> Other than that difference in track matching to
the FCAL in data vs. simulation, initially noted
by Alex, Igal raises a lack of calibration of 2017
data for the inner blocks.</li>
<li> It is not clear that a fiducial cut is needed
to exclude inner blocks from their role as a
backup t-zero setter for tracking. The energy is
not used, only the time and position in this
context.</li>
<li> Sean will review the status of the 2017
calibration.</li>
</ul>
</li>
<li> <a rel="nofollow" class="external text" href="https://github.com/JeffersonLab/HDGeant4/issues/195">Crash
adding daughters on RHEL/CentOS 8</a>
<ul>
<li> We think this one is resolved but are still
waiting for Hao Li to confirm the fix.</li>
</ul>
</li>
<li> <a rel="nofollow" class="external text" href="https://github.com/JeffersonLab/HDGeant4/issues/191">Add
incident angle dependence to DIRC mirror
reflectivity</a>
<ul>
<li> This enhancement remains on the books. Richard
will consult with the DIRC folks to see if they
have done any further thinking on this. In
principle, implementation is straightforward.</li>
</ul>
</li>
</ul>
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