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<p>Present: Raphael, Bayram, Stepan, Xiaohui, Hovanes, Yohann, Cole
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<p>On the phone: Sebastian </p>
<p>Notes by Hovanes
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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_March_9_meeting#DC_calibrations">1 DC calibrations</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_March_9_meeting#RTPC_calibrations">2 RTPC calibrations</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_March_9_meeting#EC_calibrations">3 EC calibrations</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_March_9_meeting#CC_calibrations">4 CC calibrations</a></li>
<li class="toclevel-1"><a href="http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_March_9_meeting#Plans_for_a_Pass0_cooking">5 Plans for a Pass0
cooking</a></li>
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<h2> DC calibrations </h2>
<ul>
<li> Bayram talked to Mac regarding the issue of x-vs-t and
residual fits. According to Mac we do nto need to do another x-vs-t
fit. The residual fit is the final fit if the figures from that fit
look good. </li>
<li> Mac told Bayram that the dc3 plots looked already nice, and
his conclusion was that we were very close to finalizing DC
calibrations. </li>
</ul>
<ul>
<li> Stepan looked at some EC calibration files and noticed that
invariant mass of e<sup>+</sup>e<sup>-</sup>
pairs is angle dependent. This may be due to the inadequate
extrapolation of the trajectory into the solenoid's field and an
inaccurate determination of the vertex location. This will have to be
studied and special correction need to be developed or borrowed from
Bonus run group. </li>
</ul>
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<h2> RTPC calibrations </h2>
<ul>
<li> Stepan reported that there was a meeting last Thursday to
discuss the RTPC calibrations. The issue with the double peaking in <b>s-dist</b>
distributions was most likely resolved, and some of the aspects of RTPC
calibration were discussed in more details. </li>
</ul>
<ul>
<li> Raphael pointed out that the He4 elastic events do not cover
all pads before of the phi-segmentation of CLAS itself. Stepan thought
that this should not be a problem since thre should not be much
phi-dependence for the electron drift parameters. Therefore it is
likely that we can use the same parameters for the pads which were not
covered by elastic events.
</li>
</ul>
<ul>
<li> Stepan requested that we cook RTPC calibration data at 1 GeV
keeping only high level BOS banks (SEB banks) and RTPC related banks,
and also filter events containing elastic events. This should simplify
the RTPC calibrations. </li>
</ul>
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<h2> EC calibrations </h2>
<ul>
<li> Cole Smith performed EC gain calibrations based on cosmic runs
and verified with electrons. He up dated database with the new
constants. </li>
<li> Cole also noticed that quality of the calibrations are not
uniform over the face of the EC. He suspects that the attenuation
lengths of the scintillators decreased with time. He sees a larger
difference between the attenuation lengths determined from the CLAS
data and measurements on the stand than it was ~10 years ago. </li>
<li> Cole will try to change the attenuation lengths and
recalibrate the gains and see if it improves the E/P plots. He will
also try to use pi0s to crosscheck the gain calibrations. </li>
</ul>
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<h2> CC calibrations </h2>
<ul>
<li> Hovanes compared the constants from the 3 CC calibrations
performed by Maurizio. </li>
<li> The SPE constants from a dedicated CC calibration runs were
systematically higher (by ~!0%) than than those from the two production
runs. </li>
<li> The constants from the two production runs were consistent
between each other. </li>
<li> Conclusions were that we do not need to do more CC calibrations
unles we see a problem. </li>
<li> The two constant sets from the production runs are linked to the
eg6 runindex in caldb. </li>
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<h2> Plans for a Pass0 cooking </h2>
<ul>
<li> We discussed a schedule for a Pass0 with the first set of
calibration constants. The pass will contain 5%-10% percent of the
data. The agreement was to aim at April 2nd. </li>
<li> The system which will need to be ready by that time are: </li>
</ul>
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<ol>
<li> DC
</li>
<li> EC
</li>
<li> TOF
</li>
<li> CC </li>
<li> IC
</li>
</ol>
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