Nuclear Physics Seminar
"Low pT photon production at confinement: The missing piece to the direct photon puzzle"
Presented by Dr. Sarah Campbell, Columbia University
Tuesday, May 19, 2015, 11 am
Small Seminar Room, Bldg. 510
Hosted by: Jin Huang
Low pT direct photons in Au+Au collisions are produced in excess of the TAA-scaled p+p yields and with a large azimuthal anisotropy, v2. This talk considers that these low pT direct photons are produced by radially boosted quarks undergoing soft-gluon mediated quark-anti-quark interactions as the system becomes color-neutral. A Monte Carlo simulation of direct photons and Chi-squared comparisons of the published PHENIX direct photon and identified particle v2 data are used to test this description. The Monte Carlo simulation reproduces the shape of the direct photon pT excess and the resulting direct photon v2 agrees, despite being systematically low, with the published 0-20% and 20-40% Au+Au low pT direct photon v2 in both centralities. Comparisons to recent preliminary direct photon results will also be shown.