Ultraviolet avalanche in anisotropic non-Abelian plasmas

We present solutions of coupled particle-field evolution in classical U(1) and SU(2) gauge theories in real time on three-dimensional lattices. Our simulations are performed in a regime of extreme anisotropy of the momentum distribution of hard particles where backreaction is important. We find qualitatively different behavior for the two theories when the field strength is high enough that non-Abelian self-interactions matter for SU(2). It appears that the energy drained by a Weibel-like plasma instability from the particles does not build up exponentially in soft transverse magnetic fields but instead returns, isotropically, to the hard scale via a rapid avalanche into the ultraviolet.