Renormalizability aspects of massive Yang--Mills field models

We confront the problem concerning the renormalizability of massive Yang--Mills theories in which the mass term for the vector fields has been inserted by hand. Our starting Lagrangians are of a type in the past found to be nonrenormalizable. The massive Yang--Mills fields are split into transverse and longitudinal components. The latter carry all the nonrenormalizability pathologies which manifest themselves in terms of certain nonpolynomial factors involving the longtitudinal fields. The removal of the bad nonpolynomial terms (Boulware's problem) is studied within the context of the adjoint representation of the gauge group SU(2). A necessary condition for solving Boulware's problem is the introduction of extra fields. We find an explicit solution which requires the introduction of a triplet of scalar fields belonging to the adjoint representation of SU(2). We interpret the additional fields as ghost, or superfluous, fields, most probably corresponding to the ghost fields of spontaneously broken gauge theories in the R gauge. Out interpretation of the fields which combine with the longitudinal ones in order to remove the nonpolymomial factors as ghost fields is not evident in the treatment of Cornwall et al. Unlike the case of Cornwall et al., we do not just show the existence of the trnasformation which removes the undesirable terms, but also give the explicit conditions which bring about this result in the case of SU(2). A proposition relating the models under consideration to spontaneously broken gauge ones is also presented. We argue, without explicit proof, that the combination of this proposition with out main theorem corresponds to building a spontaneously broken gauge theory in the R gauge, having started from a non-Abelian theory with mass inserted by hand