RENORMALIZATION AND THE EQUIVALENCE THEOREM - ON-SHELL SCHEME

We perform an exhaustive analysis of the equivalence theorem both in t he minimal standard model and in an effective electroweak chiral Lagra ngian up to O(p(4)). We have considered the leading corrections to the usual prescription consisting in just replacing longitudinally polari zed W or Z by the corresponding Goldstore bosons. The corrections appe ar through an overall constant multiplying the Goldstone boson amplitu de as well as through additional diagrams. By including them we can ex tend the domain of applicability of the equivalence theorem, making it suitable for precision tests of the symmetry-breaking sector of the s tandard model. The on-shell scheme has been used throughout. When cons idering the equivalence theorem in an effective chiral Lagrangian we a nalyze its domain of applicability, as well as several side issues con cerning gauge fixing, Ward identities, the on-shell scheme, and matchi ng conditions in the effective theory. We analyze in detail the proces ses W+W- --> W+W- and W+W+ --> W+W+ to illustrate the points made.