From Quarks and Gluons to Hadrons: Chiral Symmetry Breaking in Dynamical QCD

TL;DR

This paper investigates the transition from high-energy quark-gluon interactions to low-energy hadron dynamics in two-flavour QCD using a functional renormalisation group approach with dynamical hadronisation, revealing how low-energy phenomena emerge from fundamental quark-gluon interactions.

Contribution

It introduces a novel application of functional renormalisation group techniques combined with dynamical hadronisation to study chiral symmetry breaking in two-flavour QCD.

Findings

Demonstrates the emergence of low-energy hadron degrees of freedom from quark-gluon dynamics.

Provides a nonperturbative description of the transition between regimes.

Shows consistency with physical quark masses.

Abstract

We present an analysis of the dynamics of two-flavour QCD in the vacuum. Special attention is payed to the transition from the high energy quark-gluon regime to the low energy regime governed by hadron dynamics. This is done within a functional renormalisation group approach to QCD amended by dynamical hadronisation techniques. The latter allow us to describe conveniently the transition from the perturbative high-energy regime to the nonperturbative low-energy limit without suffering from a fine-tuning of model parameters. In the present work, we apply these techniques to two-flavour QCD with physical quark masses and show how the dynamics of the dominant low-energy degrees of freedom emerge from the underlying quark-gluon dynamics.