We study the possible mixings between gauge vector fields and scalar fields through their self-energies, arising in models with two Higgs doublets. We derive the relevant set of Schwinger-Dyson equations and the Ward identities that compel the longitudinal parts of the field propagators. Linear $(R_{ \xi})$ gauge is used and the results are given at all orders in perturbative theory, and some particular aspects of the one loop case are stressed.
Categories: hep-ph