<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><span style="font-size: 13px;">Theory Center Seminar</span></div><div><span style="font-size: 13px;">Monday, Nov. 21, 2016</span><br style="font-size: 13px;"><span style="font-size: 13px;">2:45 p.m.</span><br style="font-size: 13px;"><span style="font-size: 13px;">CEBAF Center, Room </span><font size="2">F324/325 </font><br style="font-size: 13px;"><b><font><span style="font-size: 15px;">Dmitrij Siemens (Bochum U.)</span></font></b><br style="font-size: 13px;"><b><span style="font-size: 15px;">Title: "Pion-Nucleon Scattering in Chiral Perturbation Theory"</span></b><br style="font-size: 13px;"><font color="#0f61c8" size="2" style="font-size: 14px;"><br></font><span style="font-size: 14px;">Abstract: </span></div><pre style="orphans: 2; widows: 2; word-wrap: break-word; white-space: pre-wrap;"><div>Elastic pion-nucleon scattering is analyzed in the framework of chiral perturbation theory</div><div>at the full one-loop order with explicit Delta degrees of freedom.</div><div>The analysis is performed in the small scale expansion within the heavy baryon and</div><div>a covariant approach based on the extended on mass-shell renormalization scheme.</div><div>The pertinent low-energy constants contributing to the pion-nucleon scattering amplitude</div><div>are extracted from fits to experimental scattering data as well as subthreshold parameters.</div><div>A novel approach to estimate the theoretical uncertainty based on the truncation of the chiral</div><div>series is employed in the fitting procedure. The obtained results for the various pion-nucleon</div><div>scattering observables are presented and discussed.</div></pre><br></body></html>