Neutron-Proton-Converter Acceleration Mechanism at Subphotospheres of Relativistic Outflows

TL;DR

This paper investigates a neutron-proton conversion acceleration mechanism in relativistic outflows, demonstrating its potential to accelerate nucleons efficiently and enhance high-energy neutrino detection.

Contribution

It introduces a novel neutron-proton conversion acceleration process at subphotospheric shocks in relativistic outflows, with numerical analysis of energy spectra and efficiency.

Findings

Significant fraction of nucleons can be accelerated.

Mechanism enhances potential for detecting GeV-TeV neutrinos.

Applicable to radiation-mediated shocks in relativistic outflows.

Abstract

We study a type of particle acceleration that operates via neutron-proton conversion in inelastic nuclear collisions. This mechanism can be expected for relativistic shocks at subphotospheres if relativistic outflows contain neutrons. Using a test-particle approximation, we numerically calculate the energy spectrum and the efficiency of accelerated particles, and show that a good energy fraction of the nucleons can be accelerated. This mechanism may especially be relevant if the shock is radiation-mediated, and it would enhance the detectability of GeV-TeV neutrinos.