Multiphoton production at high energies in the standard model. I

We examine multiphoton production in the electroweak sector of the standard model in the high-energy limit using the equivalence theorem in combination with spinor helicity techniques. We obtain recursion relations for currents consisting of a charged scalar, spinor, or vector line that radiates n photons. Closed form solutions to these recursion relations for arbitrary n are presented for the cases of like-helicity and one unlike-helicity photon production. We apply the currents singly and in pairs to obtain amplitudes for processes involving the production of n photons with up to two unlike helicities from a pair of charged particles. The replacement of one or more photons by transversely polarized Z bosons is also discussed.