High energy photon-neutrino elastic scattering

The one-loop helicity amplitudes for the elastic scattering process γν⃗γν 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 √s=2ω, the cross section grows roughly as ω⁶ to near the threshold for W-boson production, √s=m_W. Although suppressed at low energies, we find that the elastic cross section exceeds the cross section for γν⃗γγν when √s>13GeV. 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.