Heavy quark interactions and quarkonium binding

We consider heavy quark interactions in quenched and unquenched lattice QCD. In a region just above the deconfinement point, non-Abelian gluon polarization leads to a strong increase in the binding. Comparing quark-antiquark and quark-quark interaction, the dependence of the binding on the separation distance r is found to be the same for the colorless singlet Q (Q) over bar and the colored anti-triplet QQ state. In a potential model description of in-medium J/psi behavior, this enhancement of the binding leads to a survival up to temperatures of 1.5 T-c or higher; it could also result in J/psi flow.