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    <div class="moz-cite-prefix">Zisis et al,<br>
      <br>
      Here's the references for radiative eta(') decays:<br>
      <br>
      First check out Daniel Lersch's conference proceeding Figure 2 for
      an example of the split-off cut they used in WASA at COSY:  <br>
      pos.sissa.it/archive/conferences/171/352/Confinement%20X_352.pdf
      .   The GlueX version of an appropriate contour cut might be
      developed by comparing signal and background in E_gamma vs
      Distance (ie, distance between a track and a shower). <br>
      <br>
      A few other papers (putting * next to the two references that
      might represent the state of the art for the eta' Dalitz plot):<br>
      <br>
      Measurement of
      Gamma(eta-->pi+pi-gamma)/Gamma(eta-->pi+pi-pi0) with the
      KLOE detector, D. Babusci et al., Physics Letters B 718 (2013)
      910-914.  <a class="moz-txt-link-freetext"
href="http://www.sciencedirect.com/science/article/pii/S0370269312011975">http://www.sciencedirect.com/science/article/pii/S0370269312011975</a><br>
      <br>
      * Model-independent approach to eta -->pi+pi-gamma and
      eta'-->pi+pi-gamma, F. Stollenwerk et al., Physics Letters B
      707 (2012) 184-190 . <br>
      <a class="moz-txt-link-freetext"
        href="http://arxiv.org/abs/1108.2419">http://arxiv.org/abs/1108.2419</a><br>
      <br>
      Exclusive measurement of the eta --> pi+pi-gamma decay, P.
      Adlarson et al. (WASA-at-COSY Collaboration), Physics Letters B
      707 (2012) 243-249.  <a class="moz-txt-link-freetext"
        href="https://arxiv.org/abs/1107.5277">https://arxiv.org/abs/1107.5277</a><br>
      <br>
      * Measurement of the decay distribution of eta' --->pi+pi-gamma
      and evidence of the box anomaly, A. Abele et al. (the Crystal
      Barrel Collaboration), Physics Letters B 402 (1997) 195-206 .  <a
        class="moz-txt-link-freetext"
href="http://www.sciencedirect.com/science/article/pii/S0370269397004796"><a class="moz-txt-link-freetext" href="http://www.sciencedirect.com/science/article/pii/S0370269397004796">http://www.sciencedirect.com/science/article/pii/S0370269397004796</a></a>
      <br>
      <br>
      Study of Dalitz Plot Distributions of the Decays
      eta-->pi+pi-pi0 and eta-->pi+pi-gamma, J.G. Layter et al.,
      Phys. Rev. D 7 (1973) p. 2565.<br>
      <a class="moz-txt-link-freetext"
        href="http://journals.aps.org/prd/abstract/10.1103/PhysRevD.7.2565">http://journals.aps.org/prd/abstract/10.1103/PhysRevD.7.2565</a><br>
      <br>
      There are some branching ratio studies done by CLEO (2009) and
      BES2 (2005) which I have only skimmed. However, their S/B ratios
      for eta'-->pi+pi-gamma were at least 10:1 at the time with good
      statistics. This begs the question of where this study is headed:
      to commission GlueX with a challenging decay branch?, define cuts
      for a large eta' branch for potential use in the hybrid program?,
      use this branch as one of several ways to measure the xsect or
      Sigma asymmetry for eta' photoproduction?, attempt a competitive
      Dalitz plot measurement?, ... all of the above? <br>
      <br>
      regards,<br>
      <br>
      Dave<br>
      <br>
      <br>
      <br>
      <br>
      <br>
      On 4/24/2016 2:59 PM, Zisis Papandreou wrote:<br>
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      Hi folks:
      <div class=""><br class="">
      </div>
      <div class="">we’ll have our next Eta/Eta-prime Working Group
        meeting on Monday April 25 at 3pm EDT.  The agenda is here:</div>
      <div class=""><a moz-do-not-send="true"
href="https://halldweb.jlab.org/wiki-private/index.php/Eta/Eta-Prime_Meeting_2016-04-25"
          class="">https://halldweb.jlab.org/wiki-private/index.php/Eta/Eta-Prime_Meeting_2016-04-25</a></div>
      <div class=""><br class="">
      </div>
      <div class="">Cheers, Zisis...<br class="">
        <div class="">
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                                              Dr. Zisis Papandreou</font></div>
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                      class="Apple-style-span" color="#929292">Email:</font>  </span><a
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                    href="mailto:zisis@uregina.ca"><a class="moz-txt-link-abbreviated" href="mailto:zisis@uregina.ca">zisis@uregina.ca</a></a></div>
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                      color="#929292" face="Verdana">Website:</font> <a
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href="http://www.uregina.ca/science/physics/people/faculty-research/zisis-papandreou/index.html"><a class="moz-txt-link-freetext" href="http://www.uregina.ca/science/physics/people/faculty-research/zisis-papandreou/index.html">http://www.uregina.ca/science/physics/people/faculty-research/zisis-papandreou/index.html</a></a></div>
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