A Analysis of Pion Photoproduction.

A partial-wave analysis of pion photoproduction data up to a photon lab energy of 1.8 GeV has been performed. Both energy-dependent and energy-independent solutions have been obtained. The energy-dependent parametrization incorporates the recently determined elastic pion nucleon scattering amplitudes in such a way as to satisfy unitarity and utilize the resonance structure contained in the pion nucleon elastic amplitudes. Starting from the energy-dependent solution, energy-independent partial-wave solutions are obtained at a set of energies from threshold to 1.8 GeV. The data base used in the analysis contains 11,971 data from the reactions gamma + p to p + pi^0, gamma + p to n + pi^{+}, gamma + n to n + pi ^0 and gamma + n to p + pi^{-} . The predictions of our solution are compared with the experimental data and previous analyses. Suggestions are made for future experiments. A total of sixteen resonances exist in the energy range from threshold to 1.8 GeV. These resonance states are studied using our energy-independent solutions. Photon decay couplings to the sixteen resonances are extracted. These couplings are also compared with previous solutions and quark model predictions.