Neutrino scattering and flavor transformation in supernovae

TL;DR

This paper explores how scattered neutrinos outside the neutrinosphere can significantly impact neutrino flavor transformation during supernova explosions, suggesting the need for revised models in this critical phase.

Contribution

It introduces the importance of direction-changing scattering of neutrinos outside the neutrinosphere in supernovae, highlighting the potential inadequacy of standard flavor transformation models during shock revival.

Findings

Scattered neutrinos influence flavor transformation during supernova shock revival.

Standard models are adequate at late times but may fail during explosion phases.

A new modeling paradigm is needed to incorporate scattered neutrino effects.

Abstract

We argue that the small fraction of neutrinos that undergo direction-changing scattering outside of the neutrinosphere could have significant influence on neutrino flavor transformation in core-collapse supernova environments. We show that the standard treatment for collective neutrino flavor transformation is adequate at late times, but could be inadequate in the crucial shock revival/explosion epoch of core-collapse supernovae, where the potentials that govern neutrino flavor evolution are affected by the scattered neutrinos. Taking account of this effect, and the way it couples to entropy and composition, will require a new paradigm in supernova modeling.