Kaon photoproduction: Data consistency, coupling constants, and polarization observables

The process γp→${\mathit{K}}^{+}$Λ is studied in a phenomenological approach. A thorough analysis of the existing differential cross section data up to 1.4 GeV, taking into account the systematic uncertainties, shows the Orsay data to be internally inconsistent. Removing this data set from the data base results in a rather simple reaction mechanism with the extracted main kaon-hyperon-nucleon coupling constants in agreement with the SU(3) predictions. Employing a diagrammatic model, the differential and total cross section, Λ-polarization, and polarized target data are well reproduced. Predictions for other single and double polarization observables and suggestions for new measurements are presented. Applying crossing symmetry, the reaction is related to the radiative ${\mathit{K}}^{\mathrm{-}}$ capture process, and a comparison with the measured branching ratio is made.