Two-component approach to $J/\psi$ $p_t$-Spectra at SPS and RHIC

We investigate $J/\psi$ transverse-momentum distributions as well as their centrality dependence in Pb-Pb collisions at SPS and Au-Au collisions at RHIC within the framework of a two-component model, which includes (i) a primordial contribution coupled with various phases of dissociation, (ii) a statistical coalescence of $c$ and $\bar{c}$ quarks at the hadronization phase transition. We use a transport equation combined with expanding fireball equations to study the component (i) and use a blast-wave approach to study the component (ii). The influence of various physical mechanisms on the $J/\psi$ $p_t$ distributions are investigated, together with applications to experimental data.