The QCD vacuum and its hadronic excitations

TL;DR

This paper surveys non-perturbative QCD phenomena, highlighting lattice QCD, chiral effective theories, and the quest for quasiparticles, providing insights into hadronic excitations and QCD thermodynamics.

Contribution

It offers a comprehensive overview of recent developments in non-perturbative QCD, integrating lattice results, effective field theories, and quasiparticle concepts.

Findings

Summarizes key lattice QCD results.

Reviews chiral effective field theory applications.

Discusses the role of quasiparticles in QCD thermodynamics.

Abstract

A survey is given on selected topics of physics in the non-perturbative, hadronic sector of the QCD phase diagramme. Following a brief QCD primer, some highlights of Lattice QCD are summarised. Chiral effective field theory as the low-energy realisation of QCD is reviewed, with applications in pion-pion scattering, the scalar form factor of the nucleon and the interpolation of nucleon properties between lattice QCD results and actual observables. Chiral SU(3) dynamics, incorporating the strange quark, is developed with examples relating to low-energy kaon-nucleon interactions. The quest for quasiparticles in QCD and their correlations, beyond the simple partonic pictures of hadron structure, is discussed and aspects of QCD thermodynamics are explored in this context.