Behavior of charmonium systems after deconfinement

We present a study of charmonia in hot gluonic plasma, for temperatures up to three times the deconfinement transition temperature $T_c.$ $q\overline{q}$ systems with quark masses close to the charm mass and different spin-parity quantum numbers were studied on very fine isotropic lattices. The analysis of temporal correlators, and spectral functions constructed from them, shows that the $J/\psi$ and ${\eta }_c$ survive up to quite high temperatures, with little observable change up to ${1.5T}_c,$ and then gradually weaken and disappear by ${3T}_c.$ For the scalar and axial vector channels, serious modifications are induced by the hot medium already close to $T_c,$ possibly dissociating the mesons by ${1.1T}_c.$