Off-shell structure of the anomalous Z and gamma self-couplings - art. no.073012

We establish the general off-shell structure of the three neutral gauge bos on self-couplings V-1*V-2*V-3*, with applications to the Z*Z*Z*, Z*Z* gamma *, gamma*gamma*Z* cases. New coupling forms appear which do not exist when two gauge bosons are on shell We give the contribution arising from a fermi onic triangle loop. It covers both the standard model (SM) and possible new physics (NP) contributions such as those arising in the minimal supersymme tric SM. For what concerns NP contributions with a high scale, we discuss t he validity of an effective Lagrangian involving a limited set of parameter s. Finally we write the general expression of the V-1*V-2*V-3*-vertex contr ibution to the e(+)e(-) --> (f (f) over bar) + (f'(f) over bar') amplitude.