Nucleon-Nucleon Scattering in a Strong External Magnetic Field and the Neutrino Emissivity

TL;DR

This paper investigates how extremely strong magnetic fields in neutron stars significantly alter nucleon-nucleon scattering and consequently impact neutrino emission rates, using the one-pion-exchange approximation.

Contribution

It introduces a detailed analysis of NN scattering in strong magnetic fields and quantifies its effect on neutrino emissivity in neutron stars.

Findings

NN cross-section can increase up to tenfold in strong magnetic fields.

Neutrino emissivity can be dramatically affected by magnetic fields in neutron stars.

Magnetic fields of 10^{15}-10^{18} G significantly influence neutron star cooling processes.

Abstract

The nucleon-nucleon scattering in a large magnetic background is considered to find its potential to change the neutrino emissivity of the neutron stars. For this purpose we consider the one-pion-exchange approximation to find the NN cross-section in a background field as large as $10^{15}\texttt{G}-10^{18}\texttt{G}$. We show that the NN cross-section in neutron stars with temperatures in the range 0.1-5 \texttt{MeV} can be changed up to the one order of magnitude with respect to the one in the absence of the magnetic field. In the limit of the soft neutrino emission the neutrino emissivity can be written in terms of the NN scattering amplitude therefore the large magnetic fields can dramatically change the neutrino emissivity of the neutron stars as well.