Tau Neutrino Decays and Big Bang Nucleosynthesis

Abstract

We investigate the non-radiative decay during nucleosynthesis of a massive tau neutrino with mass 0.1 - 1 MeV into an electron neutrino and a scalar or pseudoscalar particle, $\varphi$. The full Boltzmann equation is used and shown to give markedly different results than the usual non-relativistic formalism for relativistic or semi-relativistic neutrino decays. Indeed, the region we investigate is where the formalism that has previously been applied to solving this problem is expected to break down. We also compare the nucleosynthesis predictions from this scenario with results from the standard model and with some of the available observational determinations of the primordial abundances. It is found that for relativistic or semi-relativistic decays the helium abundance can be significantly lowered without changing other light element abundances. Since a problem with the standard model of Big Bang nucleosynthesis is that helium appears to be overproduced, a decay of the type we discuss can be a possible solution.

7 pages RevTeX, 6 figures. To be published in Phys. Rev. D

References in corpus (1)

• Neutrinos in Physics and Astrophysics

Cited by in corpus (18)

• Neutrinos in cosmology
• Radiative decay of a massive particle and the non-thermal process in primordial nucleosynthesis
• Third Generation Familons, B Factories, and Neutrino Cosmology
• Big bang nucleosynthesis limit on N_nu
• Cosmological Constraints on Invisible Neutrino Decays Revisited
• Cosmological Nucleosynthesis and Active-Sterile Neutrino Oscillations with Small Mass Differences: The Nonresonant Case
• Inhomogeneous Big-Bang Nucleosynthesis in Light of Recent Observations
• Big Bang Nucleosynthesis with Matter--Antimatter Domains
• Cosmological nucleosynthesis and active-sterile neutrino oscillations with small mass differences: The resonant case
• Search for the Familon via $B^{\pm }\to {\pi }^{\pm }{X}^0$, $B^{\pm }\to K^{\pm }{X}^0$, and $B^0\to K_S^0{X}^0$ Decays
• Implications of the ${\nu }_{\mu }\to {\nu }_s$ solution to the atmospheric neutrino anomaly for early Universe cosmology
• Photon Spectrum Produced by the Late Decay of a Cosmic Neutrino Background
• Probing neutrino decays with the cosmic microwave background
• Unstable massive tau-neutrinos and primordial nucleosynthesis
• Constraining neutrino decays with CMBR data
• Decay-Produced Neutrino Hot Dark Matter
• Alternative Solutions to Big Bang Nucleosynthesis
• Post freeze-out annihilations in the early universe