A quark model test by radiative processes of eta and eta' mesons

It is shown that the recent data on radiative processes of eta (and eta')-mesons, eta(eta') → 2 gamma and psi → eta(eta') + gamma , are interpreted quite naturally in terms of the quark structures of eta- and eta'-mesons based on the model of broken SU(3) x U(1) symmetry of the vacuum proposed earlier. In describing the former processes, the non-negligible effects of I = Y = 0 particle mixing as well as the on-shell corrections to the soft-meson amplitudes are taken into consideration. The integral charge model is seen unfavorable but not excluded completely. (author)