Hidden Local Symmetry for Anomalous Processes with Isospin/SU(3) Breaking Effects

We show that isospin/SU(3) breaking terms can be introduced to the anomalous VVP coupling in the hidden local symmetry scheme without changing Wess-Zumino-Witten term in the low-energy limit. We make the analysis for anomalous processes of 2-body and 3-body decays; radiative vector meson decays(V \to P\gamma), conversion decays of photon into a lepton pair(V \to P l^+ l^-) and hadronic anomalous decays(V \to PPP). The predictions successfully reproduce all experimental data of anomalous decays. In particular, we predict the decay widths of \rho^0 \to \pi^0 \gamma and \phi \to \eta' \gamma as 101 \pm 9 keV and 0.508 \pm 0.035 keV, respectively, which will be tested in the DAFNE \phi-factory. Moreover, prediction is also made for \phi \to \pi^0 e^+ e^-, \rho \to 3\pi, K^* \to K \pi \pi and so on, for which only the experimental upper bounds are available now.Comment: 19 pages, 4 tables, no figur

Radiative Decays, Nonet Symmetry and SU(3) Breaking

We re-examine the problem of simultaneously describing in a consistent way all radiative and leptonic decays of light mesons (V -> P gamma, P -> V gamma, P -> gamma gamma, V -> e^+ e^-). For this purpose, we rely on the Hidden Local Symmetry model in both its anomalous and non--anomalous sectors. We show that the SU(3) symmetry breaking scheme proposed by Bando, Kugo and Yamawaki, supplemented with nonet symmetry breaking in the pseudoscalar sector, allows one to reach a nice agreement with all data, except for the K^{*+/-} radiative decay. An extension of this breaking pattern allows one to account for this particular decay mode too. Considered together, the whole set of radiative decays provides a pseudoscalar mixing angle theta_P ~ -11^o and a value for theta_V which is ~ 3^o from that of ideal mixing. We also show that it is impossible, in a practical sense, to disentangle the effects of nonet symmetry breaking and those of glue inside the eta', using only light meson decays.Comment: 36 pages. Published versio