Momentum dependent vertices ???, ??? and ??? the NJL scalar hidden by chiral symmetry

We calculate the momentum dependence of three particle vertices sigma gamma gamma, sigma rho gamma and sigma rho rho in the context of a Nambu Jona Lasinio type model. We show how they influence the processes gamma gamma-->sigma-->pi pi, rho-->gamma sigma and gamma gamma-->rho rho and how chiral symmetry shadows the presence of the sigma.