An analysis of pion-nucleon scattering

A phase-shift analysis of elastic pion-nucleon scattering data g from threshold to a pion kinetic energy of 1100 MeV was performed. The resulting partial-wave amplitudes were investigated in the complex energy plane, and the resonance states with their associated zeros and poles were determined. Particular emphasis was given on elucidating the nature of the P₁₁ partial wave.

The phase-shift analysis consisted of both energy-independent and energy-dependent analyses. The energy dependent partial waves were parametrized as a coupled channel K-matrix whose elements are polynomials in energy plus an explicit pole term.

A complete description of the investigation and the experimental data used are included as is a description of the theoretical models used for interpretation of the results.