Nuclear matter within a dilatation-invariant parity doublet model: the role of the tetraquark at nonzero density

TL;DR

This paper explores how a scalar tetraquark influences nuclear matter properties within a dilatation-invariant parity doublet model, highlighting its impact on condensates and chiral symmetry restoration at high density.

Contribution

It introduces a scalar tetraquark into the parity doublet model, revealing its significant role in nuclear matter behavior and chiral symmetry restoration.

Findings

Tetraquark condensate appears alongside the chiral condensate at nonzero density.

The scalar tetraquark affects the properties of nuclear medium.

Chiral symmetry restoration is influenced by the tetraquark degree of freedom.

Abstract

We investigate the role of a scalar tetraquark state for the description of nuclear matter within the parity doublet model in the mirror assignment. In the dilatation-invariant version of the model a nucleon-nucleon interaction term mediated by the lightest scalar tetraquark field naturally emerges. At nonzero density one has, beyond the usual chiral condensate, also a tetraquark condensate. The behavior of both condensates and the restoration of chiral symmetry at high density are studied. It is shown that this additional scalar degree of freedom affects non negligibly the properties of the medium.