Nucleon Resonances in the π−p → K0Γ Reaction near Threshold

Abstract

We investigate the two-body reaction π−p → K0Γ within the effective Lagrangian approach and the isobar model. In addition to the “background” contributions from t-channel K* exchange, u-channel Σ(1192) and Σ*(1385) exchanges, and s-channel nucleon pole terms, the contributions from the nucleon resonances N* (1535), N* (1650), and N* (1720) are investigated. It is shown that the inclusion of these nucleon resonances contributions leads to a good description of the experimental total and differential cross sections data at low energy region. The s-channel N* (1535), N* (1650), and N* (1720) resonances and the t-channel K* exchange give the dominant contributions below W = 1.76 GeV, while the s-channel nucleon pole, u-channel Σ(1192) and Σ*(1385) exchanges give the minor contributions.