Physics of neutrino flavor transformation through matter-neutrino resonances

TL;DR

This paper investigates how matter-neutrino resonances influence neutrino flavor transformations in dense astrophysical environments, revealing hierarchy-dependent sensitivities and explaining the process via adiabatic solutions akin to the MSW mechanism.

Contribution

It demonstrates that neutrino flavor transformation through MNRs can be understood through multiple adiabatic solutions and highlights hierarchy-dependent differences in sensitivity to spectral shapes and adiabaticity.

Findings

Flavor transformation sensitive to spectral shape in normal hierarchy

Transformation insensitive to spectral shape in inverted hierarchy

Flavor evolution explained by multiple adiabatic solutions

Abstract

In astrophysical environments such as core-collapse supernovae and neutron star-neutron star or neutron star-black hole mergers where dense neutrino media are present, matter-neutrino resonances (MNRs) can occur when the neutrino propagation potentials due to neutrino-electron and neutrino-neutrino forward scattering nearly cancel each other. We show that neutrino flavor transformation through MNRs can be explained by multiple adiabatic solutions similar to the Mikheyev-Smirnov-Wolfenstein mechanism. We find that for the normal neutrino mass hierarchy, neutrino flavor evolution through MNRs can be sensitive to the shape of neutrino spectra and the adiabaticity of the system, but such sensitivity is absent for the inverted hierarchy.