Chiral symmetry, scalar field and confinement : from nucleon structure to nuclear matter

TL;DR

This paper explores how the interplay between chiral symmetry breaking and confinement influences nucleon structure and nuclear matter stability, emphasizing the role of scalar modes in chiral theories.

Contribution

It introduces models demonstrating the importance of the balance between chiral symmetry breaking and confinement for nuclear matter saturation.

Findings

Nuclear matter stability depends on a mixed origin of nucleon mass.

Scalar modes in chiral theories impact nuclear matter properties.

Chiral constraints and confinement alter QCD sum rule predictions.

Abstract

We discuss the relevance of the scalar modes appearing in chiral theories with spontaneous symmetry breaking such as the NJL model for nuclear matter studies. We show that it depends on the relative role of chiral symmetry breaking and confinement in the nucleon mass origin. It is only in the case of a mixed origin that nuclear matter can be stable and reach saturation. We describe models of nucleon structure where this balance is achieved. We show how chiral constarints and confinement modify the QCD sum rules for the mass evolution in nuclear matter.