Photoproduction of KΛ on the Proton

Abstract

Making use of an isobar model, we study kaon photoproduction on the proton in the resonance region. The higher-spin nucleon, spin-3/2 and spin-5/2, and hyperon, spin-3/2, resonances were included in the model utilizing the consistent formalism proposed by Pascalutsa and they were found to play an important role in data description. The dipole and multidipole shapes of hadron form factor were selected as those most suitable for the depiction of experimental data. Model parameters were fitted to new experimental data from CLAS, LEPS, and GRAAL collaborations and two versions of the model, BS1 and BS2, were chosen. Both of them provide a good overall description of the data for the c.m. energies from the threshold up to 2.4 GeV. Since the kaon photoproduction process takes place in the third-resonance region, the total number of included resonances in the models, 15 and 16, respectively, is quite moderate in comparison with other models. The set of chosen nucleon resonances coincides well with the one specified in the Bayesian analysis with the Regge-plus-resonance model as the most probable contributing states.