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 $c\overline{c}$ 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 nonperturbative calculation of the consequences of a wind velocity $v$ on the screening length $L_s$ for a heavy quark-antiquark pair in hot $\mathcal{N}=4$ 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.

• Received 18 July 2006

DOI:https://doi.org/10.1103/PhysRevLett.98.182301