Speaker
Description
Charmonia, the bound states of a charm quark (c) and its antiquark ($\bar{c}$), are dissociated in a deconfined medium through color Debye screening and hard partonic collisions. Charmonium suppression is therefore regarded as a diagnostic probe of quark-gluon plasma (QGP) formation in relativistic heavy-ion collisions. A rigorous interpretation of their suppression pattern induced by the hot and dense medium, however, requires a robust characterization of the dissociation mechanisms operative already in normal nuclear matter or Cold Nuclear Matter (CNM), across systems ranging from proton-nucleus (p+A) to nucleus-nucleus (A+A) collisions. In this contribution, we present a unified phenomenological prescription for studying the influence CNM effects on charmonium production in relativistic nuclear collisions. We examine the full spectrum of different mechanisms believed to induce CNM suppression at the successive stages of quarkonium production, and quantify the contribution of each in a systematic, data-driven manner. Using this framework, we provide a baseline estimate for $\mathrm{J/\psi}$ production in Pb+Pb and In+In collisions at the lower SPS energies, and likewise in Pb+Pb and Au+Au collisions at the higher LHC and RHIC energies. Comparison with published experimental data has been carried out whenever possible. Finally, the model yields predictions for the charmonium suppression due to CNM effects in p+A and A+A collisions at the forthcoming NA60+ experiment at the CERN SPS and the CBM experiment at FAIR.