Supernova neutrinos: Strong coupling effects of weak interactions

TL;DR

This paper investigates the strong coupling effects of weak interactions on neutrino flavor evolution in supernovae, demonstrating that simplified models remain valid in complex multi-angle simulations.

Contribution

It provides a detailed analysis of collective neutrino oscillations considering full multi-angle effects, confirming the robustness of simplified analytical approaches.

Findings

Main features of collective oscillation regimes are preserved in multi-angle simulations.

Simplified models like the pendulum analogy remain valid in complex scenarios.

Strong coupling effects significantly influence neutrino flavor evolution in supernovae.

Abstract

In core-collapse supernovae, neutrinos and antineutrinos are initially subject to significant self-interactions induced by weak neutral currents, which may induce strong-coupling effects on the flavor evolution (collective transitions). The interpretation of the effects is simplified when self-induced collective transitions are decoupled from ordinary matter oscillations, as for the matter density profile that we discuss. In this case, approximate analytical tools can be used (pendulum analogy, swap of energy spectra). For inverted neutrino mass hierarchy, the sequence of effects involves: synchronization, bipolar oscillations, and spectral split. Our simulations shows that the main features of these regimes are not altered when passing from simplified (angle-averaged) treatments to full, multi-angle numerical experiments.