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<h1 class="firstHeading">Minutes of the Meeting on January 4 at
9:30am</h1>
<h3 id="siteSub">From Lowqwiki</h3>
<p>Present: F.-X., Carlos, Bayram, Hovanes.
</p>
<p>On the phone: Lamiaa, Dave
</p>
<p>Notes by Hovanes.
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<p><br>
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<h2>Contents</h2>
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<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_Meeting_on_January_4_at_9:30am#IC_calibrations">1 IC
calibrations</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_Meeting_on_January_4_at_9:30am#DC_calibrations">2 DC
calibrations</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_Meeting_on_January_4_at_9:30am#Software_status">3 Software
status</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_Meeting_on_January_4_at_9:30am#EC_fiducial_cuts">4 EC
fiducial cuts</a></li>
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<h2> IC calibrations </h2>
<dl>
<dd> F.-X. reported on the progress of IC energy calibrations
<ul>
<li> Invariant mass mean values from all channels are at
μ=134.9 MeV. The energy resolution is σ=9.6 MeV which is a
little larger than from the previous IC experiments where σ
was 7 or 8 MeV. Might be to not optimal calibrations, some
noisy channels, correction for vertex position, lower energy
cutoff in photon selection (400 MeV instead of 800 MeV) to
increase the statistics. </li>
<li> F.-X. did eight iterations, he showed plot of π<sup>0</sup>
mass versus iteration number with four sets of points. The
red points are with simple parameterization by F.-X. for
energy corrections, the blue points are with more
complicated Rustam's parameterizations. The lower two sets
of points are the mass of the π<sup>0</sup> , the upper sets
of points are mass of the π<sup>0</sup> plus the resolution.
</li>
<li> Resolution seems to have converge, no improvement is seen
with iterations anymore. </li>
<li> Timing calibrations are still off, F.-X. may not have
time to work on it. It would be good if someone could work
on it. </li>
</ul>
</dd>
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<p><br>
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<h2> DC calibrations </h2>
<dl>
<dd> Lamiaa reported on the activities related to DC calibrations.
<ul>
<li> Seema did another iteration for 1 GeV runs. She did not
see overall improvement in the residuals, although some
particular showed some improvements. </li>
<li> We are still using the old constants. We need to decide
if we should go ahead with the old constants or wait for new
ones from Seems for 6 GeV. </li>
</ul>
</dd>
</dl>
<p><br>
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<h2> Software status </h2>
<dl>
<dd>
<ul>
<li> The software is pretty much ready for Pass1.
</li>
<li> Lamiaa fixed some bugs which were causing seg. faults.
These were related to array boundary crossing in ICHB and
GCPB and were fixed by increasing the array sizes. </li>
<li> We will have ntuple, log-file, 2 ROOT files, helicity
correction text file. We will have 1 single BOS file for
both event types: negative TB track; and positive track with
two neutrals. </li>
<li> F.-X. looked at the data event-by-event in the "h2root"
ROOT file and noticed some duplicate events with identical
event number in the HEAD bank. This need to be checked in
other files as well. We need to keep this in mind if we do
not fix this. </li>
</ul>
</dd>
</dl>
<p><br>
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<h2> EC fiducial cuts </h2>
<dl>
<dd> Dave looked at U, V, W distributions of the hits in EC to
determine the fiducial cuts on the face of EC.
<ul>
<li> Dave was taking the U, V, W values from the ntuple
itself. </li>
<li> F.-X. suggested to calculate the U, V, W coordinates from
the global X, Y, Z coordinates because one may miss some of
U, V, W but still have all global coordinates. Stepan could
clarify this issue. F.-X. will send a C++ routine to
calculate U, V, W from X, Y, Z .
</li>
<li> F-X also pointed out that at low values of U there can be
"shadow" events from IC (junk from IC leaking into EC).
</li>
</ul>
</dd>
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