Quarks and baryons in QCD at finite density

TL;DR

This paper explores how finite quark density modifies the confining string in QCD, revealing a potential phase transition to multiquark hadrons at high densities relevant to heavy ion collisions and neutron stars.

Contribution

It introduces a novel analysis of string behavior at nonzero chemical potential, predicting a new multiquark phase transition in dense matter.

Findings

Finite quark density significantly alters the confining string.

An attractive well appears in multiquark systems at high density.

A phase transition to multiquark hadrons is predicted at 3-4 nuclear densities.

Abstract

The mechanism of string creation for light quarks developed earlier is considered for nonzero quark chemical potential. A strong modification of the confining string due to finite quark density (chemical quark potential $\mu$) is observed. As a surprising result in a multiquark system with a common string junction an attractive well appears of radius $\mu/\sigma$ and of an average depth equal to $\mu$, which induces formation of multiquark hadrons. Preliminary estimates predict a new phase transition to multiquark hadron phase at rather high densities (in heavy ion collisions or in neutron stars) when neutron matter is compressed to 3-4 normal nuclear densities.