Heavy quarks at RHIC from parton transport theory

There are several indications that an opaque partonic medium is created in energetic Au+Au collisions at the relativistic heavy ion collider (RHIC). At the extreme densities of ∼10–100 times normal nuclear density reached, even heavy-flavor hadrons are affected significantly. Heavy-quark observables are presented from the parton transport model MPC, focusing on the nuclear suppression pattern, azimuthal anisotropy (“elliptic flow”), and azimuthal correlations. Comparison with Au+Au data at top RHIC energy indicates significant heavy-quark rescattering, corresponding roughly five times higher opacities than estimates based on leading-order perturbative QCD. We propose measurements of charm–anticharm, e.g., D-meson azimuthal correlations as a sensitive, independent probe to corroborate these findings. PACS 25.75.-q; 25.75.Ld; 25.75.Gz