Informal Pizza Seminar

Heavy quark diffusion in perturbative QCD at next-to-leading order

Simon Caron Huot

McGill

I present our recent calculation of the momentum diffusion coefficient of a nonrelativistic heavy quark in a hot QCD plasma, at next-to-leading order in the weak coupling expansion. After briefly introducing the quark gluon plasma and how it is probed experimentally at RHIC, I discuss the physics of the next-to-leading order correction (which arises at O(g)). I argue that the weak coupling expansion converges poorly, and that the present-day perturbative estimates of quantities measured at RHIC might be plagued with large, O(1), errors.