Unstable massive tau-neutrinos and primordial nucleosynthesis
High Energy Physics - Phenomenology
2009-09-25 v2
Abstract
The impact of unstable Majorana tau neutrinos on primordial nucleosynthesis is considered. The mass and lifetime of nu_tau are taken in the intervals 0.1-20 MeV and 0.001-400 sec respectively. The studied decay modes are nu_tau -> nu_mu + phi and nu_tau -> nu_e + phi, where phi is a massless (or light) scalar. Integro-differential kinetic equations are solved numerically without any simplifying assumptions. Our results deviate rather strongly from earlier calculations. Depending on mass, lifetime, and decay channels of the nu_tau, the number of effective neutrino species (found from He4), in addition to the 3 standard ones, varies from -2 to +2.5. The abundances of H2 and Li7 are also calculated.
Keywords
Cite
@article{arxiv.hep-ph/9809598,
title = {Unstable massive tau-neutrinos and primordial nucleosynthesis},
author = {A. D. Dolgov and S. H. Hansen and S. Pastor and D. V. Semikoz},
journal= {arXiv preprint arXiv:hep-ph/9809598},
year = {2009}
}
Comments
36 pages including 28 figures, minor changes