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<p class="xxmsonormal" align="center" style="text-align:center"><b><span style="font-size:28.0pt;font-family:"Times New Roman",serif">Hall D Seminar</span></b><o:p></o:p></p>
<p class="xxmsonormal" align="center" style="text-align:center"><span class="xxvalue"><b><span style="font-size:28.0pt;font-family:"Times New Roman",serif">Andrew Schick<o:p></o:p></span></b></span></p>
<p class="xxmsonormal" align="center" style="text-align:center"><span class="xxvalue"><b><span style="font-size:28.0pt;font-family:"Times New Roman",serif">March 29, 2024 9:00-9:55 A.M.<o:p></o:p></span></b></span></p>
<p class="xxmsonormal" align="center" style="text-align:center"><b><span style="font-size:26.0pt;font-family:"Times New Roman",serif">Zoom:
</span></b><span style="font-size:16.0pt"><a href="https://jlab-org.zoomgov.com/j/1605251012?pwd=UVVwcGs4bWduNnhLRFRHTjVON21Ydz09">https://jlab-org.zoomgov.com/j/1605251012?pwd=UVVwcGs4bWduNnhLRFRHTjVON21Ydz09</a>
</span><o:p></o:p></p>
<p align="center" style="text-align:center"><i><span style="font-size:20.0pt;font-family:"Times New Roman",serif">Lepton Pair Production Studies at GlueX and Future Applications<o:p></o:p></span></i></p>
<p align="center" style="text-align:center"><b><span style="font-size:18.0pt">Abstract:<o:p></o:p></span></b></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Segoe UI Semibold",sans-serif">Lepton pair production has played an important role in both nuclear and particle physics, being among the earliest calculations utilizing QED, and seen most famously
in the discovery of the $J/\psi$ at BNL. This seminar presents an overview of studies involving lepton pairs in the GlueX and Charged Pion Polarizability data sets, and how those efforts are naturally extended to assist future experimental programs in Hall
D. A technique is presented for measuring the linear polarization of GeV scale photon beams through the detection of $e^+e^-$ pairs photo-produced in the target.
<br>
It is demonstrated that these $ e^+e^- $ pairs in the GlueX 2018 data set are also sensitive to the proton charge form factor, which opens up the possibility for a new method to measure the proton RMS charge radius. To facilitate these studies (and also to
eliminate pair backgrounds in the CPP experiment), neural nets were trained for $ e/\pi $ and $ \mu/\pi $ identification at forward angles.
<br>
Both of these neural nets can be extended to cover a wider phase space, and modified to include new features from the planned GEM TRD that is soon to be installed in Hall D to help identifiy $ J/\psi $ events through both electron and muon pairs. <o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Patricia Cheeseboro<o:p></o:p></p>
<p class="MsoNormal">Admin Support Physics (Hall D)<o:p></o:p></p>
<p class="MsoNormal">Thomas Jefferson National Accelerator Facility<o:p></o:p></p>
<p class="MsoNormal">Jefferson Science Associates, LLC<o:p></o:p></p>
<p class="MsoNormal"><a href="mailto:pcheese@jlab.org">pcheese@jlab.org</a><o:p></o:p></p>
<p class="MsoNormal">(757) 269-5345<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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