NEW SEMICLASSICAL NON-ABELIAN VERTEX OPERATORS FOR CHIRAL AND NONCHIRAL WZW THEORY

We supplement the discussion of Moore and Reshetikhin and others by fi nding new semi-classical non-Abelian vertex operators for the chiral, antichiral and nonchiral primary fields of WZW theory. These new non-A belian vertex operators are the natural generalization of the familiar Abelian vertex operators: they involve only the representation matric es of Lie g, the currents of affine (g x g) and certain chiral and ant ichiral zero modes, and they reduce to the Abelian vertex operators in the limit of Abelian algebras. Using the new constructions, we also d iscuss semiclassical operator product expansions, braid relations and relations to the known form of she semiclassical affine-Sugawara confo rmal blocks.