The momentum diffusion coefficient for heavy quarks is studied in a
deconfined gluon plasma in the static approximation by investigating a
correlation function of the color electric field using Monte Carlo techniques.
The diffusion coefficient is extracted from the long distance behavior of such
a correlator. For temperatures Tc < T <~ 2 Tc, our nonperturbative estimate of
the diffusion coefficient is found to be very different from the leading order
perturbation theory, and is in the right ballpark to explain the heavy quark
flow seen by PHENIX at RHIC.Comment: Minor changes, version to appear in Physical Review
