Radiative decays, nonet symmetry, and SU(3) breaking

We reexamine the problem of simultaneously describing in a consistent way all radiative and leptonic decays of light mesons (→VPγ, →PVγ, →Pγγ, →Ve⁺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 θP-11^∘ and a value for θV which is 3^∘ 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 η^', using only light meson decays.