Total Cross Sections for Scattering and Absorption of Pions by Nuclei

The causality conditions of Goldberger for the pion-nucleon scattering have been used to calculate the parameter $k_1$ of the optical model for scattering of pions from nuclei. These values of $k_1$ together with values of the absorption coefficient $K$ in nuclear matter were used to obtain the total absorption and diffraction cross sections of pions for carbon, copper, and lead in the range 0-2.5 Bev.