A Relativistic Quantum Approach to Neutrino and Antineutrino Emissions via the Direct Urca Process in Strongly Magnetized Neutron-Star Matter

TL;DR

This paper develops a relativistic quantum model to analyze neutrino emissions via the direct Urca process in strongly magnetized neutron-star matter, revealing magnetic fields enable the process in previously forbidden density regions.

Contribution

It introduces a quantum approach solving for Landau level states, showing magnetic fields facilitate the direct Urca process in neutron-star matter.

Findings

Magnetic fields enable the Urca process at lower densities.

Exact wave functions for protons and electrons are derived.

Neutrino emissivity is quantitatively calculated.

Abstract

We study neutrino and antineutrino emission from the direct Urca process in neutron-star matter in the presence of strong magnetic fields. We calculate the neutrino emissivity of the direct Urca process, whereby a neutron converts to a proton, an electron and an antineutrino, or a proton-electron pair converts to a neutron-neutrino pair. We solve exact wave functions for protons and electrons in the states described with Landau levels. We find that the direct Urca process can satisfy the kinematic constraints even in density regions where this process could not normally occur in the absence of a magnetic field.