Massive Gauge Theory and Weak Form Factors

Closely following the theory of Yang and Mills, massive gauge theories are formulated for a four-vector field which is a mixture of spin-1 and spin-0 particles. The gauge invariance of theories can be maintained within the present framework even for massive spin-1 particles. Furthermore, interactions can also be generated for spin-0 particles. The usual gauge transformation for massive electrodynamics is discussed, as well as the chiral gauge transformations. The interactions so generated are shown to lead to the modified Goldberger-Treiman relation.