Abstract
We derive general constraints on the relic abundances of a long-lived particle which mainly decays into a neutrino (and something else) at cosmological time scales. Such an exotic particle may show up in various particle-physics models based on physics beyond the standard model. The constraints are obtained from big bang nucleosynthesis, cosmic microwave background, and diffuse neutrino and photon fluxes, depending on the lifetime and the electromagnetic and hadronic branching ratios.
- Received 5 June 2007
DOI:https://doi.org/10.1103/PhysRevD.76.105017
©2007 American Physical Society
