Interplay between SU (Nf) chiral symmetry, U (1)A axial anomaly, and massless bosons

Azcoiti, Vicente (Universidad de Zaragoza)

Resumen: The standard wisdom on the origin of massless bosons in the spectrum of a quantum field theory (QFT) describing the interaction of gauge fields coupled to matter fields is based on two well-known features: gauge symmetry and spontaneous symmetry breaking of continuous global symmetries. However, we will show in this article how the topological properties, which originate the U(1)A axial anomaly in a QFT that describes the interaction of fermion matter fields and gauge bosons, are the basis of an alternative mechanism to generate massless bosons in the chiral limit, if the non-Abelian SU(Nf)A chiral symmetry is fulfilled in the vacuum. We will also test our predictions with the results of a well-known two-dimensional model, the two-flavor Schwinger model, which was analyzed by Coleman long ago, and will give a reliable answer to some of the questions he asked himself on the spectrum of the model in the strong-coupling (chiral) limit. We will also analyze what the expectations for the U(N) gauge-fermion model in two dimensions are and will discuss the impact of our results in the chirally symmetric high-temperature phase of QCD, which was present in the early Universe and is expected to be created in heavy-ion collision experiments. To keep mathematical rigor, we perform our calculations using a lattice regularization and Ginsparg-Wilson fermions.

Idioma: Inglés

DOI: 10.1103/PhysRevD.100.074511

Año: 2019

Publicado en: Physical Review D 100, 7 (2019), 074511 1-14
ISSN: 2470-0010

Factor impacto JCR: 4.833 (2019)

Categ. JCR: PHYSICS, PARTICLES & FIELDS rank: 6 / 29 = 0.207 (2019) - Q1 - T1
Categ. JCR: ASTRONOMY & ASTROPHYSICS rank: 16 / 68 = 0.235 (2019) - Q1 - T1

Factor impacto SCIMAGO: 1.664 - Physics and Astronomy (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MINECO/FPA2015-65745-P

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Física Teórica (Dpto. Física Teórica)