Heavy quark diffusion as a probe of sQGP

Abstract

The heavy quarks are the interesting probes of hot matter created in relativistic heavy ion collisions. We describe the Brownian motion of heavy quarks in the hot medium by the relativistic Langevin equation. The numerical simulation of heavy quarks in the expanding fireball and its comparison to experimental data indicates that the drag force in the quark-gluon plasma is stronger than that estimated from perturbative QCD.