SINGLE PION PHOTOPRODUCTION IN QUARK MODEL

We present the results of a detailed quark model calculation of the resonance contributions to the total, and backward differential, cross sections for single-pion photoproduction off nucleons. All prominent nucleonic resonances below 2 GeV are considered and assigned to the usual quark configurations with LP=0+, 1-, 2+. The model is found to be in reasonable agreement with experiment and to predict that the main features of photoproduction off neutrons should be qualitatively different from those off protons. An experimental test is proposed for the presence of the 'spin-orbit' radiative coupling in the quark electromagnetic interaction. Finally, the same formalism is used to discuss the radiative decays of the strange Yo*(1520) and Yo*(1405) resonances. © 1969.