High-energy neutrinos in the early universe can produce electron-positron pairs by annihilating with cosmic background neutrinos. These high-energy electrons thermalize to produce a cascade of lower-energy photons which can fission light elements. We use this process to constrain "invisible" particle decays, in which a decaying particle produces neutrinos but no electromagnetically interacting particles in its decay. These limits are applied to specific neutrino and gravitino decay models.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics