Medium Modification of Charm Production in Relativistic Heavy Ion Collisions due to Pre-equilibrium Dynamics of Partons at $\sqrt{s_{\textrm {NN}}}$= 0.2--5.02 TeV

Abstract

We study the production dynamics of charm quarks in the parton cascade model for relativistic heavy ion collisions at RHIC and LHC energies. The model is eminently suited for a study of the pre-equilibrium dynamics of charm quarks at modest transverse momenta. The treatment is motivated by QCD parton picture and describes the dynamics of an ultra-relativistic heavy-ion collision in terms of cascading partons which undergo scattering and multiplication while propagating. We find considerable suppression of charm quarks production in $AA$ collisions compared to those for $pp$ collisions at the same $\sqrt{s_{\text {NN}}}$ scaled by number of collisions. This may be important for an accurate determination of energy loss suffered by charm quarks while traversing the thermalized quark gluon plasma.