Direct computation of inelastic photon-neutrino processes in the Standard Model

Abstract

In this paper, we compute the Standard Model polarized amplitudes and cross sections of the processes $γν\toγγν$, $γγ\to γν\barν$ and $ν\barν\to γγγ$, for centre-of-mass energies $ω$ within the range of validity of the Fermi theory. By using a large electron-mass expansion of the exact result, we also derive the first correction term to the effective, low-energy ($ω< m_e$) formula for $γν\toγγν$. Finally, we discuss possible astrophysical implications of our results and provide simple fits to the exact expressions.