Gluon mass scale through nonlinearities and vertex interplay

Author(s)

Aguilar, A. C. ; Ferreira, M. N. ; Figueiredo, C. T. ; Papavassiliou, J.

• Document type: Journal article
• Source: PHYSICAL REVIEW D; v. 100, n. 9, p. 19-pg., 2019-11-27.

Abstract

We present a novel analysis of the gluon gap equation, where its full nonlinear structure is duly taken into account. In particular, while in previous treatments the linearization of this homogeneous integral equation introduced an indeterminacy in the scale of the corresponding mass, the current approach determines it uniquely, once the value of the gauge coupling at a given renormalization point is used as input. A crucial ingredient for this construction is the "kinetic term" of the gluon propagator, whose form is not obtained from the complicated equation governing its evolution, but is rather approximated by suitable initial Ansatze, which are subsequently improved by means of a systematic iterative procedure. The multiplicative renormalization of the central equation is carried out following an approximate method, which is extensively employed in the studies of the standard quark gap equation. This approach amounts to the effective substitution of the vertex renormalization constants by kinematically simplified form factors of the three- and four-gluon vertices. The resulting numerical interplay, exemplified by the infrared suppression of the three-gluon vertex and the mild enhancement of the four-gluon vertex, is instrumental for obtaining positive-definite and monotonically decreasing running gluon masses. The resulting gluon propagators, put together from the gluon masses and kinetic terms obtained with this method, match rather accurately the data obtained from large-volume lattice simulations. (AU)

• FAPESP's process: 18/09684-3 - The infrared properties of the transverse structure of the quark-gluon vertex
• Grantee: Clara Teixeira Figueiredo
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 17/07595-0 - Nonperturbative aspects of the QCD Green's functions
• Grantee: Arlene Cristina Aguilar
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/11894-0 - Aspects of the dynamical mass generation in the formalism of the Schwinger-Dyson equations
• Grantee: Clara Teixeira Figueiredo
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/05685-2 - Hadronic physics in high energy nuclear collisions
• Grantee: Jun Takahashi
• Support Opportunities: Special Projects