Abstract
The high-precision cross section data for the reaction reported by the CLAS Collaboration at the Thomas Jefferson National Accelerator Facility have been analyzed based on an effective Lagrangian approach in the tree-level approximation. Apart from the -channel exchanges, the -channel nucleon () exchange, the -channel exchanges, and the generalized contact term, the contributions from the near-threshold nucleon resonances in the channel are also taken into account in constructing the reaction amplitude. It is found that to achieve a satisfactory description of the differential cross section data, at least two nucleon resonances should be included. By including the resonance, which is responsible for the shape of the angular distribution near the threshold, and one of the and resonances, one can describe the cross section data quite well, with the fitted resonance masses and widths compatible with those advocated by the Particle Data Group. The resulted predictions of the beam, target, and recoil asymmetries are found to be quite different from various fits, indicating the necessity of the spin observable data for to further pin down the resonance contents and associated parameters in this reaction.
4 More- Received 14 April 2017
- Revised 2 August 2017
DOI:https://doi.org/10.1103/PhysRevC.96.035206
©2017 American Physical Society