<html dir="ltr">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
<style type="text/css" id="owaParaStyle"></style>
</head>
<body fpstyle="1" ocsi="0">
<div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;">After a brief delay due to a PHd defense, the high energy seminar will begin at
<b>11:45</b> (5 minutes from now) in room M2035. There is also some food and coffee leftover for the defense that all are welcome to!
<div><br>
</div>
<div>-Brian<br>
<div style="font-family: Times New Roman; color: #000000; font-size: 16px">
<hr tabindex="-1">
<div id="divRpF554667" style="direction: ltr;"><font face="Tahoma" size="2" color="#000000"><b>From:</b> physics-postdoc [physics-postdoc-bounces@lists.osu.edu] on behalf of Francis, Brian<br>
<b>Sent:</b> Friday, April 13, 2018 9:00 AM<br>
<b>To:</b> physics-all@lists.osu.edu<br>
<b>Subject:</b> RE: HET/HEE Seminar: Evan Johnson, April 13th<br>
</font><br>
</div>
<div></div>
<div>
<div style="direction:ltr; font-family:Tahoma; color:#000000; font-size:10pt">A friendly reminder for all,
<b>today at 11:30am</b> in room M2035 we will hear from our very own Evan Johnson! In the High Energy seminar he'll speak on his work on EFTs for resonant wino dark matter. See you there!
<div><br>
</div>
<div>
<div style="font-size:13.3333px">Friday, April 13th, 2018</div>
<div style="font-size:13.3333px">11:30am</div>
<div style="font-size:13.3333px">M2035, Physics Research Building</div>
<div style="font-size:13.3333px"><br>
</div>
<div style="font-size:13.3333px">Speaker: Evan Johnson</div>
<div style="font-size:13.3333px">Title: Zero-Range Effective Field Theory for Resonant Wino Dark Matter</div>
<div style="font-size:13.3333px"><span style="font-family:Calibri,sans-serif; font-size:14px; background-color:rgb(255,255,255)">Dark matter in the form of weakly interacting massive particles (WIMPs) with masses at the TeV scale receive nonperturbative “Sommerfeld
enhancements” to their pair annihilation rates due to unsuppressed exchanges of weak gauge bosons before the annihilation. These enhancements are conventionally computed numerically through the solution of coupled-channel Schrödinger equations. The most dramatic
enhancements occur when there is an S-wave resonance near the WIMP-pair threshold. My collaborators and I have developed an effective field theory for wino dark matter near such a resonance. Winos interact nonperturbatively through zero-range contact interactions
as well as through the long-range Coulomb interaction. Our analytic results for wino scattering and wino-pair annihilation accurately reproduce the results calculated numerically using the Schrödinger equation. I will show how this effective field theory is
systematically improvable, how the Coulomb resummation is carried out, and how to build in the annihilation processes. Finally, I will demonstrate the power of this effective field theory by showing how a complicated process, the formation of a WIMP-pair bound
state, can be calculated analytically.</span></div>
<div style="font-size:13.3333px"><span style="font-family:Calibri,sans-serif; font-size:14px; background-color:rgb(255,255,255)"><br>
</span></div>
<div style="font-size:13.3333px"><span style="font-family:Calibri,sans-serif; font-size:14px; background-color:rgb(255,255,255)">-Brian</span></div>
<div style="font-family:Times New Roman; color:#000000; font-size:16px">
<hr tabindex="-1">
<div id="divRpF151309" style="direction:ltr"><font face="Tahoma" size="2" color="#000000"><b>From:</b> Francis, Brian<br>
<b>Sent:</b> Monday, April 09, 2018 11:32 AM<br>
<b>To:</b> physics-all@lists.osu.edu<br>
<b>Subject:</b> HET/HEE Seminar: Evan Johnson, April 13th<br>
</font><br>
</div>
<div></div>
<div>
<div style="direction:ltr; font-family:Tahoma; color:#000000; font-size:10pt">Hello all,
<div><br>
</div>
<div>This week Friday we will be hosting our very own Evan Johnson for the High Energy seminar! Please join us and hear from Evan on his work with EFTs for resonant Wino dark matter! Please not this is no the typical time or room.</div>
<div><br>
</div>
<div>Friday, April 13th, 2018</div>
<div>11:30am</div>
<div>M2035, Physics Research Building</div>
<div><br>
</div>
<div>Speaker: Evan Johnson</div>
<div>Title: Zero-Range Effective Field Theory for Resonant Wino Dark Matter</div>
<div><span style="font-family:Calibri,sans-serif; font-size:14px; background-color:rgb(255,255,255)">Dark matter in the form of weakly interacting massive particles (WIMPs) with masses at the TeV scale receive nonperturbative “Sommerfeld enhancements” to their
pair annihilation rates due to unsuppressed exchanges of weak gauge bosons before the annihilation. These enhancements are conventionally computed numerically through the solution of coupled-channel Schrödinger equations. The most dramatic enhancements occur
when there is an S-wave resonance near the WIMP-pair threshold. My collaborators and I have developed an effective field theory for wino dark matter near such a resonance. Winos interact nonperturbatively through zero-range contact interactions as well as
through the long-range Coulomb interaction. Our analytic results for wino scattering and wino-pair annihilation accurately reproduce the results calculated numerically using the Schrödinger equation. I will show how this effective field theory is systematically
improvable, how the Coulomb resummation is carried out, and how to build in the annihilation processes. Finally, I will demonstrate the power of this effective field theory by showing how a complicated process, the formation of a WIMP-pair bound state, can
be calculated analytically.</span></div>
<div><span style="font-family:Calibri,sans-serif; font-size:14px; background-color:rgb(255,255,255)"><br>
</span></div>
<div><span style="font-family:Calibri,sans-serif; font-size:14px; background-color:rgb(255,255,255)">-Brian</span></div>
<div><br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>