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<p style="margin-top:0;margin-bottom:0">Dear FX,</p>
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<p style="margin-top:0;margin-bottom:0">Anyway, I checked examples with the numerical results you mentioned in your e-mail. The check outcome is attached. My and your results coincide. So, we are on the same page. I just don't know how to read your nomogram.
I was unable to get points from them in your examples...</p>
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<p style="margin-top:0;margin-bottom:0"> Best Regards,</p>
<p style="margin-top:0;margin-bottom:0"> Victor
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> clas12_rgk <clas12_rgk-bounces@jlab.org> on behalf of Viktor Mokeev <mokeev@jlab.org><br>
<b>Sent:</b> Wednesday, December 12, 2018 10:20:34 PM<br>
<b>To:</b> Francois-Xavier Girod-Gard<br>
<b>Cc:</b> Rafayel Paremuzyan; clas12 rgk; clas12 first exp<br>
<b>Subject:</b> Re: [clas12_rgk] trigger efficiency vs ECal treshold</font>
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<p style="margin-top:0; margin-bottom:0">Dear FX,</p>
<p style="margin-top:0; margin-bottom:0"><br>
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<p style="margin-top:0; margin-bottom:0"> I am not sure I understand your plots. We need to speak. I can do this tomorrow afternoon.</p>
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<p style="margin-top:0; margin-bottom:0"> Best Regards,</p>
<p style="margin-top:0; margin-bottom:0"> Victor<br>
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<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Francois-Xavier Girod <fxgirod@jlab.org><br>
<b>Sent:</b> Wednesday, December 12, 2018 9:54:55 PM<br>
<b>To:</b> Viktor Mokeev<br>
<b>Cc:</b> clas12 rgk; clas12 first exp; Rafayel Paremuzyan<br>
<b>Subject:</b> Re: [clas12_rgk] trigger efficiency vs ECal treshold</font>
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<div>
<div dir="ltr">Dear Viktor
<div><br>
</div>
<div>I have those series of over-informative plots as attached in case they can help the discussion</div>
<div>They show the kinematic coverage for a given beam energy</div>
<div><br>
</div>
<div>Units are GeV and degrees. For instance, the points</div>
<div>( Q^2 = 2 , W = 3 ) corresponds to approximately ( mom = 1.1 , theta = 30 )</div>
<div>( Q^2 = 5 , W = 2.5 ) corresponds to approximately ( mom = 1 , theta = 53 ) (this point is off scale on the plots)<br>
</div>
<div>The 35 degree angle at W = 2.5 occurs around Q^2 = 3.8 and mom = 1.6</div>
<div><br>
</div>
<div>Best regards</div>
<div>FX</div>
</div>
<br>
<div class="x_x_gmail_quote">
<div dir="ltr">On Wed, Dec 12, 2018 at 6:26 PM Viktor Mokeev <<a href="mailto:mokeev@jlab.org">mokeev@jlab.org</a>> wrote:<br>
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<p style="margin-top:0px; margin-bottom:0px">Dear All,</p>
<p style="margin-top:0px; margin-bottom:0px"><br>
</p>
<p style="margin-top:0px; margin-bottom:0px"> From FX trigger efficiency plot, I see efficiency problems at the lab. energies of the scattered electron <2.0 GeV or for \nu value above 5.5 GeV for the electron beam energy 7.5 GeV. It corresponds to the following
W ranges where we have the problem with trigger efficiency:</p>
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</p>
<p style="margin-top:0px; margin-bottom:0px">Q^2=2.0 GeV^2 W>3.0 GeV</p>
<p style="margin-top:0px; margin-bottom:0px">Q^2=5.0 GeV^2 W>2.5 GeV</p>
<p style="margin-top:0px; margin-bottom:0px"><br>
</p>
<p style="margin-top:0px; margin-bottom:0px">For hybrid baryon search, we have no any problem with the trigger efficiency at Q^2<2.0 GeV^2 since the lightest hybrids are expected in the mass range <2.5 GeV. Furthermore, the initial search for hybrid baryons
will be carried out at Q^2<2.0 GeV^2.</p>
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<p style="margin-top:0px; margin-bottom:0px"> Best Regards,</p>
<p style="margin-top:0px; margin-bottom:0px"> Victor<br>
</p>
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<div id="x_x_gmail-m_-59478190252913499divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Francois-Xavier Girod <<a href="mailto:fxgirod@jlab.org" target="_blank">fxgirod@jlab.org</a>><br>
<b>Sent:</b> Wednesday, December 12, 2018 6:09:53 PM<br>
<b>To:</b> Viktor Mokeev<br>
<b>Cc:</b> clas12 rgk; clas12 first exp; Rafayel Paremuzyan<br>
<b>Subject:</b> Re: [clas12_rgk] trigger efficiency vs ECal treshold</font>
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<div dir="ltr">Dear Viktor
<div><br>
</div>
<div>Rafo can confirmed as he produced the plot, my understanding is that the electron momentum is measured by the drift chambers</div>
<div><br>
</div>
<div>Best regards</div>
<div>FX</div>
</div>
<br>
<div class="x_x_gmail-m_-59478190252913499x_gmail_quote">
<div dir="ltr">On Wed, Dec 12, 2018 at 6:08 PM Viktor Mokeev <<a href="mailto:mokeev@jlab.org" target="_blank">mokeev@jlab.org</a>> wrote:<br>
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<p style="margin-top:0px; margin-bottom:0px">Dear FX,</p>
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<p style="margin-top:0px; margin-bottom:0px"> Just to make sure, whether P on your plots is the energy=momentum of the scattered electron?</p>
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</p>
<p style="margin-top:0px; margin-bottom:0px">Best Regards,</p>
<p style="margin-top:0px; margin-bottom:0px"> Victor<br>
</p>
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<font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> clas12_rgk <<a href="mailto:clas12_rgk-bounces@jlab.org" target="_blank">clas12_rgk-bounces@jlab.org</a>> on behalf of Francois-Xavier Girod <<a href="mailto:fxgirod@jlab.org" target="_blank">fxgirod@jlab.org</a>><br>
<b>Sent:</b> Wednesday, December 12, 2018 5:58:01 PM<br>
<b>To:</b> clas12 rgk; <a href="mailto:clas12_first_exp@jlab.org" target="_blank">
clas12_first_exp@jlab.org</a><br>
<b>Cc:</b> Rafayel Paremuzyan<br>
<b>Subject:</b> [clas12_rgk] trigger efficiency vs ECal treshold</font>
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<div dir="ltr">Dear all
<div><br>
</div>
<div>During today's meeting I attempted to have a discussion on the trigger efficiency as function of ECal threshold. Contradicting statements were made during the meeting, so I want this discussion to be on record here.</div>
<div><br>
</div>
<div>Please see the plot</div>
<div><br>
</div>
<div><a href="https://www.jlab.org/Hall-B/secure/clas12/rec_mon/P_Good_emWithEC_5786.png" target="_blank">https://www.jlab.org/Hall-B/secure/clas12/rec_mon/P_Good_emWithEC_5786.png</a><br>
</div>
<div><br>
</div>
<div>from Rafo's study of the trigger efficiency. He analyzed run 5786 which was taken with the random trigger. </div>
<div><br>
</div>
<div>- in blue all "good electrons" with Nphe>2, E_PCal > 60 MeV, sampling fraction > 0.2 and fiducial cuts</div>
<div><br>
</div>
<div>- in orange, the electrons satisfy in addition E_ECal > 300 MeV</div>
<div><br>
</div>
<div>- in red, the events for which the orange set was missing the electron trigger bit</div>
<div><br>
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<div>The trigger efficiency is defined as (orange - red) / orange</div>
<div><br>
</div>
<div><a href="https://www.jlab.org/Hall-B/secure/clas12/rec_mon/Eff_All_Good_em_trg_threshold_5786.png" target="_blank">https://www.jlab.org/Hall-B/secure/clas12/rec_mon/Eff_All_Good_em_trg_threshold_5786.png</a><br>
</div>
<div><br>
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<div>The trigger efficiency below 2 GeV drops rapidly, and measuring a cross section in this region is challenging</div>
<div><br>
</div>
<div>My question during the meeting was: do we already have data to show the trigger efficiency when the threshold is 150 MeV. My understanding is that we do not have this data and that to answer this question we need to take another random trigger run with
the lower threshold.</div>
<div><br>
</div>
<div>What I have in mind is the following: I agree that the bulk of the RG-K data taking can take place at 300 MeV ECal trigger threshold and highest possible luminosity, but I would like to consider the possibility to take a few days at a lower trigger threshold
to extend the cross section measurement to higher W. Again my purpose is to minimize the final systematic uncertainties.</div>
<div><br>
</div>
<div>Best regards</div>
<div>FX</div>
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