whose solution yields the distribution function that extremizes the entropy production (for a review of this method see [@epvm]). This procedure results in a closure for the distribution function of colored particles which has two satisfying properties: (i) it is nonlinear in the variables of the effective theory, thus generalizing Grad’s quadratic ansatz [@deGroot; @ferz; @is1; @liboff; @kremer] in a nontrivial way [@linking; @progress], and (ii) it does not rely in any way on the gradient expansion in fluid variables. The equation of motion for $\lambda^{\mu\nu}$ is then obtained from this closure by the method of moments.

The result is an effective theory for the dynamics of color fields coupled to colored particles that can handle highly nonequilibrium situations, for example the large momentum anisotropy present at early times in heavy ion collisions. Our formalism is a simplified model that shares with the true dynamics the conservation laws, Lorentz and gauge invariance, being causal, and satisfying the Second Law. In the spirit of finding the simplest possible theory incorporating the conservation laws, we postulate a simple BGK form for the collision term [@liboff; @kremer] in the Boltzmann equation, and obtain solutions at second order in the relaxation time. By going 