The exact parity symmetric model and big bang nucleosynthesis

Abstract

The assumption of exact, unbroken parity symmetry leads directly to a simple predictive resolution of the atmospheric and solar neutrino puzzles. This is because the existence of this symmetry implies the existence of a set of mirror neutrinos which must mix maximally with the known neutrinos if neutrinos have mass. The maximal mixing of the electron neutrino with the mirror electron neutrino with 3 × 10-10 eV2 ≲ |δm2| ≲ 10-3 eV2 leads to a predicted reduction of the solar neutrino flux by a factor of 2, which is in quite good agreement with the experiments. The maximal mixing of the muon neutrino with the mirror muon neutrino with |δm2| ≃ 10-2 eV2 also solves the atmospheric neutrino puzzle..