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The experimental forward pion nucleon scattering amplitude is investigated in the light of the Harari model. We find that the two are incompatible. However, over the first three resonance regions at least, we find that the resonances alone give a good approximation to the full amplitude.

Differential cross sections for π+p and π−p elastic scattering have been measured with an accuracy of typically ±2% at 10 and 9 energies respectively in the range 88 to 292 MeV of lab kinetic energy.

Measurements have been made of the π ∓ proton total cross sections over the laboratory kinetic energy range 70 to 290 MeV. The absolute accuracy of the data is generally 0.5 %, but decreases to 1 % for some points where applied corrections are large or where low particle fluxes limit the statistical accuracy. The parameters of the Δ 0 , Δ ++ resonance have been calculated, and a discussion is included on the limitations placed by Coulomb barrier effects on extracting the basic nuclear phase shifts from data in this energy region.

Measurements have been made of the total charge-exchange cross section π − p to π 0 n over the laboratory kinetic energy range 90 to 290 MeV. The data have an absolute accuracy of typically 1%, and have here been used to determine the pion-nucleon P 13 phase shift.