A unitary model for meson-nucleon scattering

Abstract

In an effective Lagrangian model employing the K-matrix approximation we extract nucleon resonance parameters. To this end we analyze simultaneously all available data for reactions involving the final states $πN$, $ππN$, $ηN$ and $K Λ$ in the energy range $m_N + m_π \le \sqrt s \le 1.9$ GeV. The background contributions are generated consistently from the relevant Feynman amplitudes, thus significantly reducing the number of free parameters.

Revised version. 60 pages, 17 figures. Two figures and a short discussion (πN \to ηN, K Λamplitudes) added, typos and minor errors in the citations corrected