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<h1 class="firstHeading">Minutes of the March 2 meeting</h1>
<h3 id="siteSub">From Lowqwiki</h3>
<p>Present: Rafayel, Carlos, Bayram, Stepan, Hovanes, Yohann
</p>
<p>On the phone: Eric, Raphael
</p>
<p>Notes by Hovanes
</p>
<p><br>
</p>
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<h2> DC calibrations </h2>
<dl>
<dd> Last week Bayram did 3 iteration with two kinds of fits: x-vs-t
and residual fits.
<ul>
<li> After residual fits the numbers for the residual on the
summary sheet looks better, but the residual versus DOCA plot shows
some variations. </li>
<li> When x-vs-t fir is performed, the variations of the
residuals vs DOCA do not disappear but they get larger. As a
consequence, the residual distributions become even worse. </li>
<li> This needs to be discussed with Mac. It is not clear if
doing the residual fit provides reasonably good x-vs-t function. </li>
</ul>
</dd>
</dl>
<dl>
<dd> Stepan also suggested to check the residuals with different
alignment constants after the calibrations are complete. Right now we
are using eg1-dvcs alignment constants determined by Bo Zhao.
</dd>
</dl>
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<h2> RTPC calibrations </h2>
<p><br>
</p>
<dl>
<dd> Yohann continued studies of <b>sdist</b> distributions, in
particular the two peaks in <b>sdist</b> at some particular z ranges. </dd>
</dl>
<dl>
<dd>
<ul>
<li> He talked to Howard about this, who suggested that
this might be due to the ALTRO chip clock. A shift in one clock pulse
of 100ns would correspond to a distance of 05.-1.0mm according to
Raphael. </li>
</ul>
</dd>
</dl>
<dl>
<dd>
<ul>
<li> Yohann showed a plot of <b>sdist</b> versus φ integrated
over all z. The plot showed acceptance-related φ-pattern of
occupancies, but little or no φ-dependence of <b>sdist</b>. </li>
</ul>
</dd>
</dl>
<dl>
<dd>
<ul>
<li> Yohann also showed a plot of <b>sdist</b> vs z, which
exhibits very abrupt and peculiar pattern. This pattern is most likely
the reason for the two peaks since a finite z-bin size would produce 2
peaks at z~0. According to Howard this pattern is an artifact of <i>gem</i>
package.
</li>
</ul>
</dd>
</dl>
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