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Dear FX,</div>
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Very good study!</div>
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I remember that we applied very efficient cut to remove radiative photons as well as background coming from the fluctuation of the electron shower in the calorimeter. We just did not consider the photons in the same sector as electron.</div>
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It worked for eta selection and will work even better for the pi0. </div>
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I think that we don't need to apply the cut on the opening angle between two photons. It is almost the same as to cut gg inv. mass. The inv mass spectrum will be fine even without top cut I believe.</div>
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Best regards,</div>
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valery</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size: 11pt;" data-ogsc=""><b>From:</b> clas12_rgk <clas12_rgk-bounces@jlab.org> on behalf of Francois-Xavier Girod <fxgirod@jlab.org><br>
<b>Sent:</b> Sunday, April 26, 2020 17:06<br>
<b>To:</b> clas12_rgk@jlab.org <clas12_rgk@jlab.org>; hybrid baryons <hybrid_baryons@jlab.org><br>
<b>Subject:</b> Re: [clas12_rgk] [EXTERNAL] Reminder: RGK meeting tomorrow at 8:00 Jlab</font>
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<div dir="ltr">Dear all
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<div>As a follow up from Friday's meeting, Anna agreed to provide me with her eppi0 simulation files so I can take a look with my code</div>
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<div>I posted some slides summarizing my findings on the docDB page here</div>
<div><a href="https://clas12-docdb.jlab.org/cgi-bin/DocDB/private/ShowDocument?docid=637" style="">https://clas12-docdb.jlab.org/cgi-bin/DocDB/private/ShowDocument?docid=637</a></div>
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<div>I think that most of the background Anna observed comes from photons generated by the electron bremsstrahlung</div>
<div>One can mostly remove all this background with a simple cut on the angle between electron and photon > 7 degrees</div>
<div>The generated kinematics indicates that such a cut should be fine</div>
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<div>In addition I applied a set of exclusivity cuts similar to what I used for the deep pi0 selection</div>
<div>Note that the values of these cuts should be adjusted for the analysis of the data, but overall I expect they would help clean up the backgrounds from other reactions as well</div>
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<div>In general it seems prudent to remove photons around the electron direction, unless one is directly interested in bremsstrahlung events</div>
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<div>Best regards</div>
<div>FX</div>
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<div dir="ltr" class="x_gmail_attr">On Thu, Apr 23, 2020 at 7:52 PM Annalisa D'Angelo <<a href="mailto:annalisa.dangelo@roma2.infn.it" style="">annalisa.dangelo@roma2.infn.it</a>> wrote:<br>
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<p><span style="background-color: rgba(255, 255, 255, 0);">Dear All,<br>
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this is a reminder of tomorrow RGK meeting <a dir="ltr" style="">at 8:00 am</a> Jlab time.<br>
<br>
The bluejeans link is:<br>
<br>
<a href="https://urldefense.proofpoint.com/v2/url?u=https-3A__jlab.bluejeans.com_214576976&d=DwMFaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=t2OnxVoP8YJyzuxpHKwj1tmrMj6s1mZ4pgV16sZJZb8&m=Xv8He5Zu2WrGWdLaLCq_bbPgPtJyiHCbvGjBnZJp-3w&s=D1duBcnVCXxtVPUS7bfmvQQ1grPEM014tffjotoLbFw&e=" dir="ltr" target="_blank" style="">https://jlab.bluejeans.com/214576976</a><br>
</span></p>
<p><span style="background-color: rgba(255, 255, 255, 0);"><br>
</span></p>
<span style="background-color: rgba(255, 255, 255, 0);">All the best<br>
<br>
Volker and Annalisa</span>
<pre cols="72">--
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Prof. Annalisa D'Angelo
Dip. Fisica, Universita' di Roma "Tor Vergata"
Istituto Nazionale di Fisica Nucleare
Sezione di Roma Tor Vergata, Rome Italy
<a href="mailto:email:annalisa.dangelo@roma2.infn.it" target="_blank" style="">email:annalisa.dangelo@roma2.infn.it</a>
Jefferson Laboratory, Newport News, VA USA
Email: <a href="mailto:annalisa@jlab.org" target="_blank" style="">annalisa@jlab.org</a>
Tel: + 39 06 72594562
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