Interplay of dynamical and explicit chiral symmetry breaking effects on a quark

Author(s)

Serna, Fernando E. ^{[1, 2, 3]} ; Chen, Chen ^[2] ; El-Bennich, Bruno ^{[2, 3]}

Affiliation

^[1] DCTA, Inst Tecnol Aeronaut, BR-12228900 Sao Jose Dos Campos, SP - Brazil

^[2] Univ Estadual Paulista, Inst Fis Teor, Rua Dr Bento Teobaldo Ferraz 271, Bloco 2, BR-01140070 Sao Paulo, SP - Brazil

^[3] Univ Cruzeiro Sul, Lab Fis Teor & Computac, Rua Galvao Bueno 868, BR-01506000 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Physical Review D; v. 99, n. 9 MAY 20 2019.
• Web of Science Citations: 0

Abstract

The relative contributions of explicit and dynamical chiral symmetry breaking in QCD models of the quark-gap equation are studied in dependence of frequently employed Ansatze for the dressed interaction and quark-gluon vertex. The explicit symmetry breaking contributions are defined by a constituent-quark sigma term whereas the combined effects of explicit and dynamical symmetry breaking are described by a Euclidean constituent-mass solution. We extend this study of the gap equation to a quark-gluon vertex beyond the Abelian approximation complemented with numerical gluon- and ghost-dressing functions from lattice QCD. We find that the ratio of the sigma term over the Euclidean mass is largely independent of nonperturbative interaction and vertex models for current-quark masses, m(u,d)(mu) <= m(mu) <= m(b)(mu), and equal contributions of explicit and dynamical chiral symmetry breaking occur at m(mu) approximate to 400 MeV. For massive solutions of the gap equation with lattice propagators this value decreases to about 200 MeV. (AU)

• FAPESP's process: 16/03154-7 - Hadrons in a nonperturbative continuum approach to QCD beyond rainbows and ladders
• Grantee: Bruno Omar El-Bennich
• Support type: Regular Research Grants
• FAPESP's process: 15/21550-4 - Continuum strong QCD: baryon masses and partonic structure
• Grantee: Chen Chen
• Support type: Scholarships in Brazil - Post-Doctorate