THERMAL DILEPTON AND OPEN CHARM SIGNALS VERSUS HARD INITIAL YIELDS INHEAVY-ION COLLISIONS AT RHIC AND LHC ENERGIES

The hard initial production of open charm and dileptons is compared wi th possible thermal signals in heavy-ion collisions at RHIC and LHC en ergies. Our approach is based on the perturbative QCD mini-jet mechani sm of quark-gluon matter formation. The thermal dilepton signal is fou nd to rise much stronger as compared to the hard Drell-Yan background with increasing collider energy and clearly dominates at LHC energy. O ppositely, open charm stems from initial hard production. A possible m anifestation of gluon shadowing at RHIC and LHC energies is discussed.