  We perform classical-statistical real-time lattice simulations to compute
real-time spectral functions and momentum broadening of quarks in the presence
of strongly populated non-Abelian gauge fields. Based on a novel methodology to
extract the momentum broadening for relativistic quarks, we find that the
momentum distribution of quarks exhibit interesting non-perturbative features
as a function of time due to correlated momentum kicks it receives from the
medium, eventually going over to a diffusive regime. We extract the momentum
diffusion coefficient for a mass range describing charm and bottom quarks and
find sizeable discrepancies from the heavy quark limit.
