Presented by Simon Caron-Huot, Institute for Advanced Study, Princeton

Friday, March 5, 2010, 2:00 pm — Small Seminar Room, Bldg. 510

We study the energy loss by bremsstrahlung for a high-energy jet moving in the quark-gluon plasma. We describe the jet perturbatively but we make no assumption about the interaction strengths in the plasma.
We propose an equation giving the radiation rate which generalizes and unify the existing treatments by Baier-Dokshitzer-Mueller-Peigne-Schiff and Zarkarov (BDMPS-Z) and by Arnold-Moore-Yaffe (AMY). Solving it numerically we can determine approximations which are valid (or not!) under RHIC conditions.
This sheds light on the discrepancy regarding the extraction of the ``$\hat{q}$'' parameter by different groups.