Resonance model for πN scattering and η-meson production in the S11 channel

A model for πN scattering and η-meson production in the S11 channel is presented. The model includes πN-scattering Born terms as well as the N∗ resonances S11 (1535) and S11 (1650). The T-matrix is computed in the K-matrix approximation. The parameters of the model are determined by fitting the elastic πN-scattering T-matrix to empirical data. We find an excellent fit for all energies up to √s = 1.75 GeV. Furthermore, a good description of the cross section for π− + p → η + n is obtained without further adjustment of parameters.