Neutron stars formed in supernovae are very intense sources of neutrinos of all species and masses 100 MeV. If such neutrinos decayed via He+e-+e- inside the Galaxy, annihilation of the trapped positrons would yield a 511-keV line exceeding the experimental bounds by many orders of magnitude. This allows us to exclude decay lifetimes in the range 104-1015 sec for neutrinos of mass 1-100 MeV. Our result corroborates and extends earlier astrophysical bounds.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)