Shockwaves in Supernovae: New Implications on the Diffuse Supernova Neutrino Background

TL;DR

This paper demonstrates that shock wave effects significantly alter the diffuse supernova neutrino background fluxes and event rates, affecting interpretations of neutrino oscillation scenarios and reducing sensitivity to collective effects.

Contribution

It introduces a detailed analysis of shock wave impacts on neutrino fluxes using hydrodynamical simulations and proposes a simplified model for future predictions.

Findings

Shock waves modify relic neutrino fluxes by about 20%.

Event rates are affected at the level of 10-20%.

Shock effects reduce sensitivity to collective oscillation effects.

Abstract

We investigate shock wave effects upon the diffuse supernova neutrino background using dynamic profiles taken from hydrodynamical simulations and calculating the neutrino evolution in three flavors with the S-matrix formalism. We show that the shock wave impact is significant and introduces modifications of the relic fluxes by about $20 \%$ and of the associated event rates at the level of $10-20 \%$. Such an effect is important since it is of the same order as the rate variation introduced when different oscillation scenarios (i.e. hierarchy or $\theta_{13}$) are considered. In addition, due to the shock wave, the rates become less sensitive to collective effects, in the inverted hierarchy and when $\sin^2 2 \theta_{13}$ is between the Chooz limit and $10^{-5}$. We propose a simplified model to account for shock wave effects in future predictions.