Moat hyperons in cold neutron stars

TL;DR

This paper explores how hyperons appear at finite momentum in neutron star matter, revealing a 'moat' region that affects the matter's composition and equation of state, emphasizing the importance of momentum-dependent interactions.

Contribution

It introduces the concept of hyperons forming a moat region at finite momentum in neutron star matter, a phenomenon previously overlooked, and demonstrates its impact on the equation of state.

Findings

Hyperons can appear at finite momentum forming a moat region.

The moat phenomenon significantly alters the hyperonic matter composition.

Momentum dependence in interactions is crucial for accurate modeling.

Abstract

We investigate the hyperonic equation of state within the non-linear derivative model that incorporates a momentum dependence on the interactions, with a special emphasis on properly establishing the conditions for hyperon appearance in neutron star matter. We demonstrate that hyperons can appear at finite momentum, forming a so-called ``moat" region, even when they are absent at lower momenta. Our study shows that this phenomenon significantly alters the composition and equation of state of hyperonic matter as compared to the cases when it is disregarded, highlighting the importance of accurately treating the momentum dependence of the baryon fields in dense matter.