Determination of the equation of state of quark matter from J/psi and Upsilon suppression at RHIC and LHC

The long lifetime of the quark-gluon plasma likely to be created in relativ istic heavy ion collisions at RHIC and LHC energies renders it sensitive to the details of the equation of state of the quark matter. We show that the p(T) dependence of the survival probability of the directly produced J/psi at RHIC energies and that of the directly produced Y at LHC energies is qu ite sensitive to the speed of sound in the quark matter: which relates the pressure and the energy density of the plasma. The transverse expansion of the plasma is shown to strongly affect the J/psi suppression at LHC energie s.