Transverse-momentum dependence of $J/\psi$ suppression in heavy-ion collisions

A central goal of heavy-ion collisions at high energies is the production of the Quark-Gluon Plasma (QGP), a new state of matter in which quarks and gluons are deconfined. A promising signature of deconfinement in these collsions may be a suppression of $J/\psi$ particles, due to the Debye screening of the strong force in the QGP. However, recent theoretical developments suggest that $J/\psi$ mesons can be regenerated via recombination of charm and anti-charm quarks in the QGP. To disentangle these mechanisms, we perform a systematic study of $J/\psi$-formation processes and investigate $J/\psi$ transverse-momentum distributions in heavy-ion collisions at different energies (at the SPS at CERN and at the Relativistic Heavy-Ion Collider at Brookhaven). We employ a two-component model to compare $J/\psi$ $p_t$ distributions to experimental data.