COVARIANT PHENOMENOLOGICAL FIELD-THEORY FOR EXTENDED HADRONS

We study the topological structure of integral equations for vertex fu nctions classified by their external points n and minimum number of in termediate-state particles i. We consider their representations not on ly in the usual covariant Minkowski space but also in the space of inv ariant distances which characterize the interactions of extended objec ts. For each topological class or skeleton diagram, the domain of inte gration over invariant lengths is compactified by the geometry of Mink owski space, combined with the topology of the diagram, the time-order ings of the vertices, and their nonlocality. We argue that the degree of compactification predicts the smoothness of each vertex contributio n and suggest how the extended structure of hadrons permits a consiste nt phenomenology with a finite set of non-local effective interactions . (C) 1995 Academic Press, Inc.