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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Quark gap equation with non-Abelian Ball-Chiu vertex

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Author(s):
Aguilar, A. C. [1] ; Cardona, J. C. [1] ; Ferreira, M. N. [1] ; Papavassiliou, J. [2, 3, 4]
Total Authors: 4
Affiliation:
[1] Univ Campinas UNICAMP, Inst Phys Gleb Wataghin, BR-13083859 Campinas, SP - Brazil
[2] Univ Valencia, Dept Theoret Phys, E-46100 Valencia - Spain
[3] Univ Valencia, IFIC, E-46100 Valencia - Spain
[4] CSIC, E-46100 Valencia - Spain
Total Affiliations: 4
Document type: Journal article
Source: Physical Review D; v. 98, n. 1 JUL 2 2018.
Web of Science Citations: 12
Abstract

The full quark-gluon vertex is a crucial ingredient for the dynamical generation of a constituent quark mass from the standard quark gap equation, and its nontransverse part may be determined exactly from the nonlinear Slav nov-Taylor identity that it satisfies. The resulting expression involves not only the quark propagator, but also the ghost dressing function and the quark-ghost kernel, and constitutes the non-abelian extension of the so-called ``Ball-Chiu vertex,{''} known from QED. In the present work we carry out a detailed study of the impact of this vertex on the gap equation and the quark masses generated from it, putting particular emphasis on the contributions directly related with the ghost sector of the theory, and especially the quark-ghost kernel. In particular, we set up and solve the coupled system of six equations that determine the four form factors of the latter kernel and the two typical Dirac structures composing the quark propagator. Due to the incomplete implementation of the multiplicative renormalizability at the level of the gap equation, the correct anomalous dimension of the quark mass is recovered through the inclusion of a certain function, whose ultraviolet behavior is fixed, but its infrared completion is unknown; three particular Ansatze for this function are considered, and their effect on the quark mass and the pion decay constant is explored. The main results of this study indicate that the numerical impact of the quark-ghost kernel is considerable; the transition from a tree-level kernel to the one computed hem leads to a 20% increase in the value of the quark mass at the origin. Particularly interesting is the contribution of the fourth Ball-Chiu form factor, which, contrary to the Abelian case, is nonvanishing, and accounts for 10% of the total constituent quark mass. (AU)

FAPESP's process: 17/05685-2 - Hadronic physics in high energy nuclear collisions
Grantee:Jun Takahashi
Support type: Research Projects - Thematic Grants
FAPESP's process: 17/07595-0 - Nonperturbative aspects of the QCD Green's functions
Grantee:Arlene Cristina Aguilar
Support type: Regular Research Grants