Nearly Degenerate Neutrinos and Broken Flavour Symmetry

1999/01/05 by Riccardo Barbieri, Lawrence J. Hall, Barbieri, Riccardo +6 · 1 citation
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Neutrino Physics Research #hep-ph

paper · pdf · doi:10.48550/arxiv.hep-ph/9901228

10 pages

arxiv created 1999/01/05 · openalex publication_date 1999/01/05 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

Theories with non-Abelian flavour symmetries lead at zeroth order to neutrino degeneracy and massless charged fermions. The flavour symmetry is spontaneously broken sequentially to give hierarchies Δm_atm² ≫ Δm_\odot² and m_τ≫ m_μ≫ m_e, and a misalignment of the vacuum between neutrino and charged sectors gives large θ_atm. Explicit models are given which determine θ_atm = 45^∘. A similar construction gives vacuum misalignment for the lighter generations and gives a vanishing ββ_{0 ν} rate, so that there is no laboratory constraint on the amount of neutrino hot dark matter in the universe, and the solar mixing angle is also maximal, θ_\odot = 45^∘.

Cited by

• Tri-bimaximal neutrino mixing from discrete subgroups of SU(3) and SO(3) family symmetry

Related

• Atmospheric and Solar neutrinos in the light of the SuperKamiokande results
• Understanding the differences in neutrino and charged-fermion flavour structures
• Massive Neutrinos as Probe of Higher Unification
• Model Bulding for the Neutrino Sector and Cold Dark Matter
• Neutrino mass hierarchy from the discrete dark matter model