Neutrino signatures of supernova turbulence

TL;DR

This paper shows that turbulence behind the shock in supernovae can be detected through neutrino signals, revealing details about the explosion mechanism and turbulence characteristics.

Contribution

It introduces a criterion for neutrino flavor depolarization due to turbulence and demonstrates its observational implications in supernova neutrino signals.

Findings

Turbulent density fluctuations affect neutrino flavor transformations.

Neutrino signals can reveal turbulence properties in supernovae.

Turbulence can obscure other features like the shock front in neutrino observations.

Abstract

Convection that develops behind the shock front during the first second of a core-collapse supernova explosion is believed to play a crucial role in the explosion mechanism. We demonstrate that the resulting turbulent density fluctuations may be directly observable in the neutrino signal starting at t>~ 3-4 s after the onset of the explosion. The effect comes from the modulation of the MSW flavor transformations by the turbulent density fluctuations. We derive a simple and general criterion for neutrino flavor depolarization in a Kolmogorov-type turbulence and apply it to the turbulence seen in modern numerical simulations. The turbulence casts a "shadow", by making other features, such as the shock front, unobservable in the density range covered by the turbulence.