Entropy Production in High Energy Processes

We calculate the entropy produced in the decoherence of a classical field configuration and compare it with the entropy of a fully thermalized state with the same energy. We find that decoherence alone accounts for a large fraction of the equilibrium entropy when each field mode is only moderately occupied. We apply this to theories of relativistic heavy ion collisions, which describe the initial state as a collection of coherent color fields. Our results suggest that decoherence may partly explain the rapid formation of a high entropy state in these collisions.