We have simultaneously analyzed the available kaon photoproduction data for the g + p ? K+ + S0, g + p ? K0 + S+, g + n ? K+ + S-, and g + n ? K0 + S0 channels by using an isobar model constructed from the Feynman diagrammatic approach for the background terms and multipoles formulation for the resonance terms. The unknown coupling constants in the background terms as well as the helicity amplitudes and the kaon branching ratios of the resonance terms were extracted by fitting the calculated observables to nearly 8000 data points from the latest experimental measurements, including the recent g + p ? K0 + S+ and g + n ? K0 + S0 data from MAMI A2 collaboration. During the fitting process we used the data listed in the Review of Particle Properties of Particle Data Group as a guidance for the resonance properties. Since in the previous study the kaon branching ratio of the N(1710)P11 state was found to be relatively large and, as a consequence, a sizable spike appeared in the K+ cross section near the threshold, in the present work we propose two isobar models, i.e. with and without this state. We have found that both models can nicely fit the data. Extensive comparisons between the result of model calculation and experimental data are presented in this paper. To investigate the role of each resonance in the present work the significance of each resonance is calculated and discussed. The present work indicates that the N(1895)S11 and ?(1900)S31 as the important resonances in the K? photoproduction. We also present two examples of application of the presented isobar models, i.e. investigation of the nucleon resonance N(1535)S11 coupling to the K? channels and the contribution of K? channels to the Gerasimov-Drell-Hearn sum rule.
|Journal||Journal of Physics G: Nuclear and Particle Physics|
|Publication status||Published - 6 Sep 2019|
- electric and magnetic multipoles
- Feynman diagram
- hadronic coupling constant
- kaon photoproduction
- nucleon resonance