Quarkonium Dissociation in a Polyakov-Nambu-Jona-Lainio Quark Plasma

We investigate the Mott effect for heavy quarkonia due to Debye screening of the heavy quark potential in a plasma of massless quarks and antiquarks. The influence of residual color correlation is investigated by coupling the light quark sector to a temporal gauge field driven by the Polyakov loop potential. This leads to an increase of the Mott dissociation temperatures for quarkonia states which stabilizes in particular the excited states, but has marginal effect on the ground states. The temperature dependence of binding energies suggests that the dissociation of the charmonium (bottomonium) ground state by thermal activation sets in at temperatures of 200 MeV (250 MeV). (authors)