Some implications of the observed decay ψ → f + γ

Describing the ψ → f+γ decay via an intermediate one-photon state avoids difficulties encountered in strong OZI- violating transitions. The ψ → γ →f+γ transition is enhanced an order of magnitude because amplitudes for the u$\text{u}$ and d$\text{d}$ components of the f are proportional to squares of quark charges and add constructively. A rough dynamical estimate agrees with the experimental decay rate. Branching ratios for f+γ,A₂+γ and f′ + γ decays are shown to be very different for electromagnetic and strong transitions and can test models. Tests of the Han-Nambu model and contributions from the weak neutral current are discussed.