Abstract
Low-energy photoproduction cross-section and polarization data are analyzed using contributions from nonresonant perturbation amplitudes associated with , , , , and propagators, and from a resonant amplitude in one total and final orbital angular momentum state. The resonance is assumed to have an energy of about 1.7 GeV and a width of about 100 MeV. The data are analyzed by assuming that the resonance can be in any one of the angular momentum states from to , and a minimization is performed for each possibility. It is found that the perturbation amplitudes alone give good fits to the cross-section data, and that only a small amount of resonant amplitude in any one of a number of angular momentum states is sufficient to explain the polarization without strongly modifying the cross-section fits. The assumed resonant state in general contributes about 20% to the total cross section, and and states give the lowest values of . The values of the coupling constants obtained herein are compared with those expected from ; approximate agreement is found though the values obtained in our analysis are generally smaller than the predictions. The possible contribution of an resonant amplitude found in the analysis is consistent with that expected from for the third resonance. A compilation of all the presently existing photoproduction data is given as an appendix.
- Received 14 February 1966
DOI:https://doi.org/10.1103/PhysRev.151.1322
©1966 American Physical Society