  As the restriction of the gauge fields to the Gribov region is taken into
account, it turns out that the resulting gauge field propagators display a
nontrivial infrared behavior, being very close to the ones observed in lattice
gauge field theory simulations. In this work, we explore for the first time a
higher correlation function in the presence of the Gribov horizon: the
ghost-anti-ghost-gluon interaction vertex, at one-loop level. Our analytical
results (within the so-called Refined Gribov Zwanziger theory) are fairly
compatible with lattice YM simulations, as well as with solutions from the
Schwinger-Dyson equations. This is an indication that the RGZ framework can
provide a reasonable description in the infrared not only of gauge field
propagators, but also of higher correlation functions, such as interaction
vertices.
