Sum rules for e(+)e(-)-> W+W- helicity amplitudes from BRS invariance

BRS invariance of the electroweak gauge theory leads to relationships betwe en amplitudes with external massive gauge bosons and amplitudes where some of these gauge bosons are replaced with their corresponding Nambu-Goldstone bosons. Unlike the equivalence theorem, these identities are exact at all energies, In this paper we discuss such identities which relate the process e(+)e(-) --> W+W- to W(+/-)chi(-/+) and chi(+)chi(-) production. By using a general form factor decomposition for e(+)e(-) --> W+W-, e(+)e(-) --> W(/-)chi(-/+) and e(+)e(-) --> chi(+)chi(-) amplitudes, these identities are expressed as sum rules among scalar form factors. Because these sum rules m ay be applied order by order in perturbation theory, they provide a powerfu l test of higher order calculations. By using additional Ward-Takahashi ide ntities we find that the various contributions are divided into separately gauge-invariant subsets, the sum rules applying independently to each subse t. After a general discussion of the application of the sum rules we consid er the one-loop contributions of scalar-fermions in the Minimal Supersymmet ric Standard Model as an illustration (C) 1999 Elsevier Science B.V.