QUANTUM STRUCTURE OF THE NON-ABELIAN WEIZSACKER-WILLIAMS FIELD FOR A VERY LARGE NUCLEUS

We consider the McLerran-Venugopalan model for calculation of the smal l-x part of the gluon distribution function for a very large ultrarela tivistic nucleus at weak coupling. We construct the Feynman diagrams w hich correspond to the classical Weizsacker-Williams field found previ ously [Yu. V. Kovchegov, Phys. Rev. D 54, 5463 (1996)] as a solution o f the classical equations of motion for the gluon field in the light-c one gauge. Analyzing these diagrams we obtain a limit for the McLerran -Venugopalan model. We show that as long as this limit is not violated a classical field can be used for the calculation of scattering ampli tudes.