Neutrino-pair bremsstrahlung from nucleon-$\alpha$ versus nucleon-nucleon scattering

TL;DR

This paper investigates how nucleon-alpha P-wave resonances influence neutrino-pair bremsstrahlung, revealing that under certain conditions, these resonances significantly enhance neutrino production in astrophysical environments like supernovae.

Contribution

It introduces the impact of nucleon-alpha P-wave resonances on neutrino bremsstrahlung, highlighting their potential importance in dense astrophysical settings, a novel aspect not extensively studied before.

Findings

Resonances enhance the nucleon spin structure factor at T < 4 MeV.

Nucleon-alpha bremsstrahlung can rival neutron-neutron processes under certain conditions.

Implications for neutrino production in supernovae environments.

Abstract

We study the impact of the nucleon-$\alpha$ P-wave resonances on neutrino-pair bremsstrahlung. Because of the non-central spin-orbit interaction, these resonances lead to an enhanced contribution to the nucleon spin structure factor for temperatures $T \lesssim 4$ MeV. If the $\alpha$-particle fraction is significant and the temperature is in this range, this contribution is competitive with neutron-neutron bremsstrahlung. This may be relevant for neutrino production in core-collapse supernovae or other dense astrophysical environments. Similar enhancements are expected for resonant non-central nucleon-nucleus interactions.