An AdS/CFT Calculation of Screening in a Hot Wind

Abstract

One of the challenges in relating experimental measurements of the suppression in the number of J/\psi mesons produced in heavy ion collisions to lattice QCD calculations is that whereas the lattice calculations treat J/\psi mesons at rest, in a heavy ion collision a c\bar c pair can have a significant velocity with respect to the hot fluid produced in the collision. The putative J/\psi finds itself in a hot wind. We present the first rigorous non-perturbative calculation of the consequences of a wind velocity v on the screening length L_s for a heavy quark-antiquark pair in hot N=4 supersymmetric QCD. We find L_s(v,T) = f(v)[1-v^2]^{1/4}/\pi T with f(v) only mildly dependent on v and the wind direction. This L_s(v,T)\sim L_s(0,T)/\sqrt{\gamma} velocity scaling, if realized in QCD, provides a significant additional source of J/\Psi suppression at transverse momenta which are high but within experimental reach.