  We perform numerical simulations of the QCD Boltzmann-Vlasov equation
including both hard elastic particle collisions and soft interactions mediated
by classical Yang-Mills fields. We provide an estimate of the coupling of jets
to a hot plasma which is independent of infrared cutoffs. For weakly-coupled
anisotropic plasmas the local rotational symmetry in momentum space is broken.
The fields develop unstable modes, forming configurations where B_t>E_t and
E_z>B_z. This provides a possible explanation for the experimental observation
that high-energy jets traversing the plasma perpendicular to the beam axis
experience much stronger broadening in rapidity than in azimuth.
