Decay of a massive neutrino in magnetized electron gas

Abstract

This paper contains a summarized calculation of the probability of massive Dirac neutrino radiative decay in an intense magnetic external field where $H\ensuremath{\gtrsim}{H}_{0}={m}_{e}^{2}{c}^{3}/e\ensuremath{\hbar}=4.41\ifmmode\times\else\texttimes\fi{}{10}^{13}\text{ }\text{ }\mathrm{G}$ with a degenerated electron gas present. It is demonstrated that the presence of the said medium significantly increases the probability of neutrino decay in the magnetic field, both in cases of relativistic and nonrelativistic neutrinos. The latter conclusion is of interest in connection with the currently developed dark matter theories, according to which dark matter may consist of nonrelativistic neutrinos with mass equal to several keV.