New cosmological limit on neutrino mass.
- Author(s): Fuller, GM
- Malaney, RA
- et al.
Published Web Locationhttps://doi.org/10.1103/physrevd.43.3136
We show that considerations of the equilibration of right- and left-handed neutrino seas in the early Universe and the well-known He4 constraint on the number of relativistic degrees of freedom extant at the nucleosynthesis epoch lead to a new limit on the Dirac neutrino mass of 300keV. This constraint would apply to any neutrino so long as it had a purely Dirac mass and a lifetime exceeding the nucleosynthesis time scale. © 1991 The American Physical Society.