Application of the Spin-Flip Dispersion Relations to the Minami Ambiguity for the Pion-Nucleon Scattering

Abstract

The dispersion relations for the spin-flip amplitude of the pion-nucleon scattering in the forward direction have been applied to the Minami phase shifts obtained from the Fermi set in a calculation similar to that of Davidon and Goldberger for the Fermi and Yang phase shifts. The Minami phase shifts were found to be in disagreement with the requirements of the dispersion relations. The same calculation was also carried out for a new set of phase shifts, which is obtained by applying the Minami transformation to the Yang phase shifts. These phase shifts are also incomqatible with the dispersion relations.