The pseudoscalar mass spectrum as evidence for gluons,anomalies and topological charge

The complete set of anomalous Ward identities for the spontaneous breaking of U(3) × U(3) applied to the pseudoscalar nonet spectrum is shown to provide evidence for gluons, gluon anomalies and non-trivial topological charge. Solutions of the Ward identities give estimates both of the average topological charge of QCD and the underlying pure Yang-Mills theory of gluons. The application of one of the Ward identities ignored in previous phenomenological analyses leads to a clearer understanding of the decays ψ→ηγ and η'γ, and explains the enhancement of SU(3) breaking effects in these decays.