Sequential charmonium dissociation

Finite temperature lattice QCD indicates that the charmonium ground state J/psi can survive in a quark-gluon plasma up to 1.5T(c) or more, while the excited states chi(c) and psi' are dissociated just above T-c. We assume that the chi(c) suffers the same form of suppression as that observed for the psi' in SPS experiments, and that the directly produced J/psi is unaffected at presently available energy densities. This provides a parameter-free description of J/psi and psi' suppression which agrees quite well with that observed in SPS and RHIC data. (c) 2006 Elsevier B.V. All rights reserved.