2 research outputs found
Bounds on Dirac Neutrino Masses from Nucleosynthesis
We derive new bounds on the Dirac mass of the tau and muonic neutrinos. By
solving the kinetic equation for the rate of energy deposition due to helicity
flipping processes and imposing the constraint that the number of effective
species contributing to the energy density at the time of nucleosynthesis be
, we find the bounds KeV and
KeV for MeV. The constraint leads to the much stronger bound KeV for both species
of neutrinos.Comment: 10 pages, UM-TH-94-21, UMN-TH-1303-94, FERMILAB-Pub-94/199-