Parity doublets and chiral symmetry restoration in baryon spectrum

TL;DR

The paper discusses how the appearance of near parity doublets in high-energy light baryons indicates chiral symmetry restoration, suggesting a phase transition at a specific quark kinetic energy level.

Contribution

It provides evidence linking parity doublets in baryon spectra to chiral symmetry restoration and identifies a phase transition at high excitation energies.

Findings

Near parity doublets appear in high-energy baryons.

Chiral symmetry restoration occurs at a critical quark kinetic energy.

A phase transition is observed in the baryon spectrum.

Abstract

It is argued that an appearance of the near parity doublets in the upper part of the light baryon spectrum is an evidence for the chiral symmetry restoration in the regime where a typical momentum of quarks is around the chiral symmetry restoration scale. At high enough baryon excitation energy the nontrivial gap solution, which signals the chiral symmetry breaking regime, disappears and the chiral symmetry should be restored. Thus one observes a phase transition in the upper part of the light baryon spectrum. The average kinetic energy of the constituent quarks in this region is just around the critical one $3T_c$.