The influence of inelastic neutrino reactions with light nuclei on the standing accretion shock instability in core-collapse supernovae

TL;DR

This study investigates how inelastic neutrino reactions with light nuclei affect the standing accretion shock instability in core-collapse supernovae, revealing their non-negligible role in shock revival through numerical simulations.

Contribution

It introduces the first detailed hydrodynamical simulations including inelastic neutrino interactions with light nuclei in supernova models.

Findings

Deuterons contribute up to 10% of neutrino heating rates.

Alpha particles heat near the shock, influencing shock dynamics.

Light nuclei interactions can both aid and hinder shock revival.

Abstract

We perform numerical experiments to investigate the influence of inelastic neutrino reactions with light nuclei on the standing accretion shock instability (SASI). The time evolution of shock waves is calculated with a simple light-bulb approximation for the neutrino transport and a multi-nuclei equation of state. The neutrino absorptions and inelastic interactions with deuterons, tritons, helions and alpha particles are taken into account in the hydrodynamical simulations in addition to the ordinary charged-current interactions with nucleons. Axial symmetry is assumed but no equatorial symmetry is imposed. We show that the heating rates of deuterons reach as high as 10% of those of nucleons around the bottom of the gain region. On the other hand, alpha particles are heated near the shock wave, which is important when the shock wave expands and the density and temperature of matter become low. It is also found that the models with heating by light nuclei have different evolutions from those without it in the non-linear phase of SASI. This results is because matter in the gain region has a varying density and temperature and there appear sub-regions that are locally rich in deuterons and alpha particles. Although the light nuclei are never dominant heating sources and they work favorably for shock revival in some cases and unfavorably in other cases, they are non-negligible and warrant further investigation.