The Boltzmann equation for gluons at early times after a heavy ion collision

A Boltzmann equation is given for the early stages of evolution of the gluon system produced in a head-on collision. The collision term is taken from gluon- gluon approximation. < p_\perp > and < p_z^2 > are evaluated as a function of time using initial conditions taken from the McLerran-Venugopalan model.