Consistent couplings between an Abelian gauge field and three types of matter
fields are investigated by means of the Hamiltonian BRST deformation theory
based on cohomological techniques. In this manner, scalar electrodynamics, the
Stuckelberg theory for Abelian zero- and one-forms, respectively, spinor
electrodynamics, are inferred.Comment: LaTeX 2e, 25 pages, to appear in Eur. Phys. J. C, Ref. [16] correcte