Low-energy πN partial wave analysis

An energy-independent partial-wave analysis has been performed on pion-nucleon elastic and charge-exchange differential cross sections and elastic polarizations, for lab. momenta below 500 MeV/c. The amplitudes were constrained by a simultaneous fixed momentum transfer analysis, which leads to a unique and smooth solution. The masses and widths of Δ⁺⁺ and Δ⁰ have been redetermined from total cross sections as m_Δ⁺⁺ = 1230.9 ± 0.3 MeV, m_Δ⁰ = 1233.6 ± 0.5 MeV, Γ_Δ⁺⁺ = 111 ± 1 MeV and Γ_Δ⁰ = 113 ± 1.5 MeV. For the pion-nucleon coupling constant the value |² = 0.079 ± 0.001 was obtained.