Nuclear Inelastic Scattering Effect in Spectra of Neutrinos at Regime of Weak Coupling with Matter

Abstract

We consider an effect of inelastic scattering in nucleon gas on the energy spectra of neutrinos during an evolution weakly coupled with hot and dense magnetized matter of dynamoactive supernovae. At a finite temperature neutrinos exhibit exo-and endoenergetic scattering on magnetized nucleons due to the Gamow–Teller neutral current interaction component. On the basis of an analysis of energy transfer properties and cross-sections due to significant additional energy exchange mechanisms arising in a magnetized nucleon gas we obtain a kinetic equation for the neutrino dynamics. It is shown that the energy transfer value magnitude and coefficient change the sign from positive to negative when the incoming neutrino energy exceeds four times the temperature of the stellar material, and almost independs on the magnetic induction. For realistic stellar parameters such effects lead to an increase in the hardness of the neutrino energy spectra, especially for the heavy lepton component. It is shown that such strengthening of neutrino hard energies is favorable for supernova neutrino observations by Large Volume Neutrino Telescopes.