High energy photon-neutrino elastic scattering

The one-loop helicity amplitudes for the elastic scattering process gamma nu-->gamma nu in the standard model are computed at high center-of-mass energies. A general decomposition of the amplitudes is utilized to investigate the validity of some of the key features of our results. In the center of mass, where roots = 2 omega, the cross section grows roughly as omega (6) to near the threshold for W-boson production, roots = m(W). Although suppressed at low energies, we find that the elastic cross section exceeds the cross section for gamma nu-->gamma gamma nu when roots >13 GeV. We demonstrate that the scattered photons are circularly polarized and the net value of the polarization is nonzero. Astrophysical implications of high energy photon-neutrino scattering are discussed.