The four-gluon vertex from lattice QCD

TL;DR

This paper reports the lattice QCD computation of the four-gluon Green function, a key but poorly understood element in non-perturbative QCD, providing new insights into its structure and form factors.

Contribution

First lattice QCD calculation of the four-gluon Green function in Landau gauge, measuring its form factors and addressing computational challenges.

Findings

Measured several form factors of the four-gluon Green function

Identified challenges in lattice computation of multi-gluon functions

Contributed to understanding non-perturbative QCD structure

Abstract

The four-gluon one-particle irreducible Green function contributes to various quantities with phenomenological relevance. An example where the four-gluon plays a role is the determination of the gluon propagator, a basic building block for QCD, using continuum methods. This four leg Green function is poorly known and we are only starting to grasp its non-perturbative structure. Here, we report on the computation of the one-particle irreducible four-gluon Green function, in the Landau gauge, with lattice simulations. Besides stating the problems associated with the computation, several form factors that characterise this Green function are measured.