Formation of quarkonium states at RHIC

At RHIC the cross section for c production will be large enough such that approximately ten pairs will be produced in each central collision. If a region of deconfined quarks and gluons is subsequently formed, one would expect that the mobility of the charm quarks will enable them to form J /ψ through `off-diagonal' combinations, involving a quark and an antiquark which were originally produced in separate incoherent interactions. We present model estimates of this effect, which indicate that the signal for deconfinement at RHIC may possibly be J /ψ enhancement rather than suppression.