COVARIANT PHENOMENOLOGICAL FIELD-THEORY FOR EXTENDED HADRONS

We study the topological structure of integral equations for vertex functions classified by their external points n and minimum number of intermediate-state particles i. We consider their representations not only in the usual covariant Minkowski space but also in the space of invariant distances which characterize the interactions of extended objects. For each topological class or skeleton diagram, the domain of integration over invariant lengths is compactified by the geometry of Minkowski space, combined with the topology of the diagram, the time-orderings of the vertices, and their nonlocality. We argue that the degree of compactification predicts the smoothness of each vertex contribution and suggest how the extended structure of hadrons permits a consistent phenomenology with a finite set of non-local effective interactions. (C) 1995 Academic Press, Inc.