High energy photon-neutrino interactions

Abstract

A general decomposition of the amplitudes for the $2\to 2$ processes $γν\toγν$ and $γγ\toν\barν$ is obtained using gauge invariance and Bose symmetry. The restrictions implied by this decomposition are investigated for the reaction $γγ\toν\barν$ by computing the one-loop helicity amplitudes in the standard model. In the center of mass, where $\sqrt{s} = 2ω$, the cross section grows roughly as $ω^6$ up to the threshold for $W$-boson production, $\sqrt{s} = 2m_W$. Astrophysical implications of very high energy photon-neutrino interactions are discussed.