Comparison of Spin-Flip Dispersion Relations with Pion-Nucleon Scattering Data

Abstract

The dispersion relations for the spin-flip, forward-scattering amplitude have been tested against pion-nucleon scattering data for energies up to 300 Mev. The Fermi set of phase shifts satisfy these relations while the Yang set do not. An approximate value for the renormalized coupling constant, $f^2={\left(\frac{g\mu }{2M}\right)}^2$, of 0.1 is obtained from the $P$-wave phase shifts.