English

Strong CP problem, theta term and QCD topological properties

High Energy Physics - Lattice 2026-03-27 v3 High Energy Physics - Phenomenology High Energy Physics - Theory

Abstract

In this chapter we introduce the θ\theta-dependence and the topological properties of QCD, features of the strongly interacting sector which give rise to the strong CP problem in the more general context of the Standard Model of particle physics. We discuss the analytical approaches that can be used to obtain qualitative, or in some cases quantitative, information on the θ\theta-dependence of QCD and QCD-like models, discussing their range of validity and comparing their predictions with the numerical results obtained by means of lattice simulations.

Keywords

Cite

@article{arxiv.2510.03059,
  title  = {Strong CP problem, theta term and QCD topological properties},
  author = {Claudio Bonanno and Claudio Bonati and Massimo D'Elia},
  journal= {arXiv preprint arXiv:2510.03059},
  year   = {2026}
}

Comments

23 pages, 2 figures, invited chapter for the Encyclopedia of Particle Physics. v2: minor revisions, typos corrected, references added. v3: further typos corrected

R2 v1 2026-07-01T06:15:23.929Z