Hadronic decays of η and η' with coupled channels

The hadronic decays η→πππ, η'→πππ and η'→ηππ are investigated within a U(3) chiral unitary approach. Final state interactions are included by deriving the effective s-wave potentials for meson-meson scattering from the chiral effective Lagrangian and iterating them in a Bethe-Salpeter equation. With only a small set of parameters we are able to explain both rates and spectral shapes of these decays