Author/Authors :
A. Abada، نويسنده , , Maria J. Matias، نويسنده , , R. Pittau، نويسنده ,
Abstract :
In this paper, we compute the Standard Model polarized amplitudes and cross sections of the processes γν → γγν, γγ → γνν and νν → 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 < me) formula for γν → γγν. Finally, we discuss possible astrophysical implications of our results and provide simple fits to the exact expressions.