  Short thermalization times of less than 1 fm/c for quark and gluon matter
have been suggested by recent experiments at the Relativistic Heavy Ion
Collider (RHIC). It has been difficult to justify this rapid thermalization in
first-principle calculations based on perturbation theory or the color glass
condensate picture. Here, we address the related question of the decoherence of
the gluon field, which is a necessary component of thermalization. We present a
simplified leading-order computation of the decoherence time of a gluon
ensemble subject to an incoming flux of Weizsacker-Williams gluons. We also
discuss the entropy produced during the decoherence process and its relation to
the entropy in the final state which has been measured experimentally.
