Symmetries in collective neutrino oscillations

Abstract

We discuss the relationship between a symmetry in the neutrino flavour evolution equations and neutrino flavour oscillations in the collective precession mode. This collective precession mode can give rise to spectral swaps (splits) when conditions can be approximated as homogeneous and isotropic. Multi-angle numerical simulations of supernova neutrino flavour transformation show that when this approximation breaks down, non-collective neutrino oscillation modes decohere kinematically, but the collective precession mode still is expected to stand out. We provide a criterion for significant flavour transformation to occur if neutrinos participate in a collective precession mode. This criterion can be used to understand the suppression of collective neutrino oscillations in anisotropic environments in the presence of a high matter density. This criterion is also useful in understanding the breakdown of the collective precession mode when neutrino densities are small.

21 pages, 2 figures. Significant revision in presentation with a new title in v2

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Cited by in corpus (7)

• Self-induced suppression of collective neutrino oscillations in a supernova
• Analysis of matter suppression in collective neutrino oscillations during the supernova accretion phase
• Evaluating approximate asymptotic distributions for fast neutrino flavor conversions in a periodic 1D box
• Collisional flavor instability in dense neutrino gases
• Flavor isospin waves in one-dimensional axisymmetric neutrino gases
• Geometric phases in neutrino oscillations with nonlinear refraction
• Neutrinos, Rare Isotopes of Exotic Nuclei and Nuclear Astrophysics