Neutron-proton mass difference in isospin asymmetric nuclear matter

TL;DR

This paper investigates how the neutron-proton mass difference varies in asymmetric nuclear matter using a medium-modified Skyrme model with pion optical potentials, revealing a strong decrease in neutron-rich environments.

Contribution

It introduces a novel approach incorporating energy-dependent pion optical potentials into the Skyrme model to study isospin-breaking effects in nuclear matter.

Findings

Neutron-proton mass difference is primarily influenced by its strong interaction component.

The mass difference decreases significantly in neutron-rich matter.

The model predicts environment-dependent modifications of baryonic properties.

Abstract

Isospin-breaking effects in the baryonic sector are studied in the framework of a medium-modified Skyrme model. The neutron-proton mass difference in infinite, asymmetric nuclear matter is discussed. In order to describe the influence of the nuclear environment on the skyrmions, we include energy-dependent charged and neutral pion optical potentials in the s- and p-wave channels. The present approach predicts that the neutron-proton mass difference is mainly dictated by its strong part and that it strongly decreases in neutron matter.