NONPERTURBATIVE QCD CONTRIBUTION TO THE GLUON-GLUON-ETA' VERTEX

We investigate the momentum dependence of the g-g-eta' vertex form fa ctor in the presence of the nonperturbative QCD vacuum condensate. The behavior of this form factor is crucial for, among Ether things, some proposed mechanisms devised to explain the large branching ratio for fast eta' production in charmless B decays observed by CLEO. We show t hat the leading momentum dependence of this vertex form factor is not altered when the contribution of the nonperturbative quark condensate is considered.