Neutrinos self interactions in Supernovae

TL;DR

This paper investigates neutrino oscillations in supernovae, focusing on collective flavor transitions caused by neutrino self interactions, and provides an analytical interpretation using a mechanical analogy.

Contribution

It offers an analytical framework for understanding collective neutrino oscillations in supernovae, especially for inverted hierarchy, using a mechanical analogy.

Findings

Identification of three regimes: synchronization, bipolar oscillations, spectral split

Averaging over trajectories does not change the regimes

Analytical interpretation via mechanical analogy

Abstract

Oscillations of neutrino emerging from a supernova core are studied. In this extremely high density region neutrino self interactions induce collective flavor transitions. When collective transitions are decoupled from matter oscillations, as for our chosen matter profile, an analytical interpretation of the collective effects is possible, by means of a mechanical analogy with a spherical pendulum. For inverted neutrino hierarchy the neutrino propagation can be divided in three regimes: synchronization, bipolar oscillations, and spectral split. Our simulation shows that averaging over neutrino trajectories does not alter the nature of these three regimes.