Onset of $J/\psi$ Melting in Quark-Gluon Fluid at RHIC

Abstract

A strong $J/\psi$ suppression in central Au+Au collisions has been observed by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). We develop a hydro+$J/\psi$ model in which hot quark-gluon matter is described by the full (3+1)-dimensional relativistic hydrodynamics and $J/\psi$ is treated as an impurity traversing through the matter. The experimental $J/\psi$ suppression pattern in mid-rapidity is reproduced well by the sequential melting of ${\chi }_{\mathrm{c}}$, ${\psi }^{\prime }$, and $J/\psi$ in dynamically expanding fluid. The melting temperature of directly produced $J/\psi$ is well constrained by the participant-number dependence of the $J/\psi$ suppression and is found to be about $2.T_{\mathrm{c}}$ with $T_{\mathrm{c}}$ being the pseudo-critical temperature.

Comments: 5 pages, 5 figures, Submitted to Phys. Rev. C. (Rapid Communication)