<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">Theory Seminar<br><div><font color="#0f61c8"><br></font>Thursday, Mar 10, 2016<br>3:30 p.m. <br>CEBAF Center, Room F113<br><font color="#0f61c8"><br></font>Raul Briceno<br>JLab/ODU<br><font color="#0f61c8"><br></font><b>Meson electro/photo-production from QCD </b><br><div><div text="#000000" bgcolor="#FFFFFF">
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<br></div></div></div></div></div></div></div></div>I present the calculation of the pi+ gamma -> pi+ pi0 transition amplitude from quantum chromodynamics. The amplitude is determined for a range of values of the photon virtuality [up to Q^2=1 GeV^2] and the final state energy. One observes a clear dynamical enhancement due to the presence of the rho-resonance. By fitting the transition amplitude and analytically continuing it onto the \rho-pole, the rho -> pi gamma form factor is obtained. This exploratory calculation, performed using lattice quantum chromodynamics, constitutes the very first determination of an electromagetic production/decay of a hadronic resonance directly from the fundamental theory of quarks and gluons. I highlight some of the necessary steps that made this calculation possible, and I discuss the status and outlook of the field for the study of N gamma -> N* -> N pi / N pi pi transitions.</body></html>