Baryon formation and dissociation in dense hadronic and quark matter

TL;DR

This paper investigates baryon formation and dissociation in hot, dense matter using a NJL-type model, revealing stable baryons only in the broken chiral symmetry phase and complex behaviors in other phases.

Contribution

It introduces a detailed Dyson-Schwinger approach to baryon and diquark propagators, highlighting the conditions for baryon stability across different phases.

Findings

Stable baryon resonances exist only in the broken chiral symmetry phase.

No baryon pole in the chirally symmetric phase.

Baryons can form as Borromean states without stable diquarks.

Abstract

We study the formation of baryons as composed of quarks and diquarks in hot and dense hadronic matter in a Nambu--Jona-Lasinio (NJL)--type model. We first solve the Dyson-Schwinger equation for the diquark propagator and then use this to solve the Dyson-Schwinger equation for the baryon propagator. We find that stable baryon resonances exist only in the phase of broken chiral symmetry. In the chirally symmetric phase, we do not find a pole in the baryon propagator. In the color-superconducting phase, there is a pole, but is has a large decay width. The diquark does not need to be stable in order to form a stable baryon, a feature typical for so-called Borromean states. Varying the strength of the diquark coupling constant, we also find similarities to the properties of an Efimov states.