Collisional triggering of fast flavor conversions of supernova neutrinos

TL;DR

This paper investigates how collisions influence fast flavor conversions of supernova neutrinos, revealing that collisions can trigger these conversions without damping oscillations, impacting supernova dynamics and neutrino signals.

Contribution

It provides the first calculations showing collisions can create conditions for fast neutrino flavor conversions while allowing oscillations to persist.

Findings

Collisions can trigger fast flavor conversions.

Oscillations can continue without significant damping.

Implications for supernova explosions and neutrino emission.

Abstract

Fast flavor conversions of supernova neutrinos, possible near the neutrinosphere, depends on an interesting interplay of collisions and neutrino oscillations. Contrary to naive expectations, the rate of self-induced neutrino oscillations, due to neutrino-neutrino forward scattering, comfortably exceeds the rate of collisions even deep inside the supernova core. Consistently accounting for collisions and oscillations, we present the first calculations to show that collisions can create the conditions for fast flavor conversions of neutrinos, but oscillations can continue without significant damping thereafter. This may have interesting consequences for supernova explosions and the nature of its associated neutrino emission.