Coupled-channels study of the π^-p→ηn process

The reaction π^-p→ηn is investigated within a dynamical coupled-channels model of meson production reactions in the nucleon resonance region. The meson baryon channels included are πN,ηN,πΔ,σN, and ρN. The nonresonant meson-baryon interactions of the model are derived from a set of Lagrangians by using a unitary transformation method. One or two excited nucleon states in each of S,P,D, and F partial waves are included to generate the resonant amplitudes. Data of the π^-p→ηn reaction from threshold up to a total center-of-mass energy of about 2 GeV are satisfactorily reproduced and the roles played by the following nine nucleon resonances are investigated: S₁₁(1535),S₁₁(1650),P₁₁(1440),P₁₁(1710),P₁₃(1720),D₁₃(1520),D₁₃(1700),D₁₅(1675), and F₁₅(1680). The reaction mechanism and the predicted ηN scattering length are discussed.