Sterile Neutrino Anarchy

TL;DR

This paper explores the concept of neutrino anarchy, suggesting that lepton mixing and potential light sterile neutrinos can be explained without complex flavor symmetries, and makes testable predictions for future experiments.

Contribution

It applies the anarchy hypothesis to the two-neutrino eV-scale seesaw model, providing a minimal framework consistent with experimental data and making specific predictions.

Findings

Anarchy distributions match global fits for active and sterile neutrinos.

Predicts no neutrinoless double beta decay.

Predicts one neutrino mass to be zero.

Abstract

Lepton mixing, which requires physics beyond the Standard Model, is surprisingly compatible with a minimal, symmetryless and unbiased approach, called anarchy. This contrasts with highly involved flavor symmetry models. On the other hand, hints for light sterile neutrinos have emerged from a variety of independent experiments and observations. If confirmed, their existence would represent a groundbreaking discovery, calling for a theoretical interpretation. We discuss anarchy in the two-neutrino eV-scale seesaw framework. The distributions of mixing angles and masses according to anarchy are in agreement with global fits for the active and sterile neutrino parameters. Our minimal and economical scenario predicts the absence of neutrinoless double beta decay and one vanishing neutrino mass, and can therefore be tested in future experiments.