Superconformal Transformation Properties of the Supercurrent II: Abelian Gauge Theories

We derive the superconformal transformation properties of the supercurrent for N=1 supersymmetric QED in four dimensions within the superfield formalism. Superconformal Ward identities for Green functions involving insertions of the supercurrent are conveniently derived by coupling the supercurrent to the appropriate prepotential of a classical curved superspace background, and by combining superdiffeomorphisms and super Weyl transformations. We determine all superconformal anomalies of SQED on curved superspace within an all-order perturbative approach and derive a local Callan-Symanzik equation. Particular importance is given to the issue of gauge invariance.