Vector-meson radiative decays and SU(3)

Recently measured radiative decay rates for vactor mesons, when compared with SU(3) and quark-model predictions, are known to disagree by factors of 2 or 3. Some simple SU(3)-breaking mechanisms in the framework of the vector-dominance model are considered, but none can fit all the data with "reasonable" parameters. It is concluded that either the new data from Primakoff-effect experiments have larger uncertainties than quoted or the usual ideas of SU(3)-invariant three-particle vertices with $U$-spin invariance for photon couplings are not valid.