Electromagnetic decays of mesons and the meson-quark coupling constants

The photonic decays of the pseudoscalar mesons πsup(o), eta and eta' are studied in the one-loop quark model and the meson-quark coupling constants are thus evaluated. The sensitivity of πsup(o) → 2γ width to the quark mass and soft pion corrections is critically discussed. The widths etasub(c) → 2γ, etasub(b) → 2γ and etasub(t) → 2γ have been evaluated. The result for the etasub(c) → 2γ width conforms with the prediction of the QCD sum rules. (author)