Colour Deconfinement and Quarkonium Binding

Quarkonium Production and Colour Deconfinement in Nuclear Collisions

The suppression of quarkonium production in nucleus-nucleus collisions was originally proposed as a signal of colour deconfinement. Strong “anomalous” J/ψ suppression in Pb-Pb collisions has been reported at this Conference by the NA50 Collaboration. Is this suppression really anomalous? Can we conclude that the quark-gluon plasma is already discovered? What has to be done next? I address these...

5 v 1 1 9 M ay 1 99 5 COLOUR DECONFINEMENT AND QUARKONIUM DISSOCIATION

String Breaking and Quarkonium Dissociation at Finite Temperatures

Recent lattice studies of string breaking in QCD with dynamical quarks determine the in-medium temperature dependence of the heavy quark potential. Comparing this to the binding energies of different quarkonium states, we check if these can decay into open charm/beauty in a confined hadronic medium. Our studies indicate in particular that the χc and the ψ ′ dissociate into open charm below the ...

Quarkonium correlators at finite temperature and potential models

We discuss the calculations of quarkonium spectral functions in potential models and their implications for the interpretation of the lattice data on quarkonium correlators. In particular, we find that melting of different quarkonium states does not lead to significant change in the Euclidean time correlators. The large change of the quarkonium correlators above deconfinement observed in the sc...

Ground State Quarkonium Spectral Functions Above Deconfinement

We discuss the temperature-dependence of S-wave quarkonium spectral functions in a nonrelativistic Green’s function approach and compare these to lattice QCD results.