Infrared facets of the three-gluon vertex

TL;DR

This paper provides new lattice QCD results for the three-gluon vertex form factors, revealing distinct infrared behaviors and validating these findings with Schwinger-Dyson analyses, enhancing understanding of nonperturbative gluon interactions.

Contribution

It introduces novel lattice calculations of the three-gluon vertex form factors in specific kinematic configurations and compares them with Schwinger-Dyson predictions, highlighting their infrared properties.

Findings

Two form factors show suppression with a negative logarithmic singularity.

One form factor saturates at a small negative constant.

Lattice results agree quantitatively with Schwinger-Dyson analysis.

Abstract

We present novel lattice results for the form factors of the quenched three-gluon vertex of QCD, in two special kinematic configurations that depend on a single momentum scale. We consider three form factors, two associated with a classical tensor structure and one without tree-level counterpart, exhibiting markedly different infrared behaviors. Specifically, while the former display the typical suppression driven by a negative logarithmic singularity at the origin, the latter saturates at a small negative constant. These exceptional features are analyzed within the Schwinger-Dyson framework, with the aid of special relations obtained from the Slavnov-Taylor identities of the theory. The emerging picture of the underlying dynamics is thoroughly corroborated by the lattice results, both qualitatively as well as quantitatively.