Self-bound quark matter in the NJL model revisited: from schematic droplets to domain-wall solitons

TL;DR

This paper revisits self-bound quark matter in the NJL model, revealing that inhomogeneous soliton structures are more stable than homogeneous droplets, with implications for quark matter dynamics.

Contribution

It demonstrates that inhomogeneous soliton-antisoliton lattices are energetically favored over homogeneous quark droplets in the NJL model.

Findings

Homogeneous solutions are unstable against soliton formation.

Single-soliton configurations minimize energy per quark.

Vector interactions influence soliton properties.

Abstract

The existence and the properties of self-bound quark matter in the NJL model at zero temperature are investigated in mean-field approximation, focusing on inhomogeneous structures with one-dimensional spatial modulations. It is found that the most stable homogeneous solutions which have previously been interpreted as schematic quark droplets are unstable against formation of a one-dimensional soliton-antisoliton lattice. The solitons repel each other, so that the minimal energy per quark is realized in the single-soliton limit. The properties of the solitons and their interactions are discussed in detail, and the effect of vector interactions is estimated. The results may be relevant for the dynamics of expanding quark matter.