Mass Effect inP-Stateπ−pScattering

The mass difference between charged and neutral mesons has been correlated to a change of the pseudovector coupling constant, giving rise to an additional term in the interaction Hamiltonian. The mass effect in $P$-state ${\pi }^{-}-p$ scattering is then calculated, using Chew's fixed-source theory. A correction to the usual scattering formula for the ${\pi }^{-}-p$ system is obtained. This correction fails to explain the quantitative feature of the observed difference (${\delta }_{13}-{\delta }_{31}$).