GLUON RADIATION AND COHERENT STATES IN ULTRARELATIVISTIC NUCLEAR COLLISIONS

We explore the correspondence between classical gluon radiation and qu antum radiation in a coherent state for gluons produced in ultrarelati vistic nuclear collisions. The expectation value of the invariant mome ntum distribution of gluons in the coherent state is found to agree wi th the gluon number distribution obtained classically from the solutio n of the Yang-Mills equations. A criterion for the applicability of th e coherent state formalism to the problem of radiation in ultrarelativ istic nucleus-nucleus collisions is discussed. This criterion is found to be fulfilled for midrapidity gluons with perturbative transverse m omenta larger than similar to 1-2 GeV and produced in collisions betwe en valence partons.