Parametric enhancement of flavor oscillation in a three-neutrino framework

TL;DR

This paper investigates how neutrino oscillations can be significantly amplified in a three-neutrino framework when traveling through matter with periodic density, extending known two-neutrino parametric resonance conditions.

Contribution

It extends the concept of parametric resonance from two-neutrino systems to a full three-neutrino framework, identifying conditions for enhancement in realistic Earth-like density profiles.

Findings

Neutrino oscillations can be enhanced two- to threefold.

Enhancement occurs when two specific approximate relations are satisfied.

The Earth's density profile can induce parametric resonance effects.

Abstract

When neutrinos travel through matter with a periodic density profile, the neutrino oscillation probability can be enhanced if certain conditions are satisfied. In a two-neutrino framework, the condition for parametric resonance is known. Herein, we consider the analogous parametric resonance condition within the context of a full three-neutrino framework with two oscillation scales. For energies in the range of hundreds of MeV to a few GeV, we find that neutrino oscillation can be parametrically enhanced if two approximate relations are satisfied. The first is similar to the two-neutrino parametric resonance condition while the second involves the other oscillation scale. Treating the Earth's density as piecewise constant, we show that oscillations in this energy range can be enhanced between two- and threefold.