J/ψ suppression in an equilibrating parton plasma

Short-distance QCD is employed to calculate the $J/\psi$ survival probabilityin an equilibrating parton gas, whose evolution is governed by a set of masterrate equations. Partons in the early stage of high-energy nuclear collisionsmay initially not be in equilibrium, but their average transverse momentum issufficiently high to break up a $Q\bar{Q}$ bound state. Such a break-up duringthe evolution of the parton gas is shown to cause a substantial $J/\psi$suppression at both RHIC and LHC energies, using realistic estimates of theinitial parton densities. The transverse momentum dependence of the suppressionis also shown to be sensitive to the initial conditions and the evolutionhistory of the parton plasma.Comment: 13 pages in RevTex, 5 uuencoded postscript figures include