A Big-Bang Nucleosynthesis Limit on the Neutral Fermion Decays into Neutrinos

TL;DR

This paper investigates how the decay of heavy sterile neutrinos and their magnetic moments influence primordial element abundances, providing new constraints from Big Bang nucleosynthesis data.

Contribution

It introduces a novel approach to constrain sterile neutrino decay properties using light element abundances from Big Bang nucleosynthesis.

Findings

Constraints on sterile neutrino decay rates derived from element abundances

Limits on neutrino magnetic moments based on nucleosynthesis data

Implications for sterile neutrino models in cosmology

Abstract

Using the primordial helium abundance, an upper limit to the magnetic moments for Dirac neutrinos had been provided by imposing restrictions on the number of the additional helicity states. Considering non-thermal photons produced in the decay of the heavy sterile mass eigenstates due to the neutrino magnetic moment, we explore the constraints imposed by the observed abundances of all the light elements produced during the Big Bang nucleosynthesis.