Energy dependence of the absorptiveS-wave pion-nucleus optical potential

Abstract

It is shown that the simplest two-body pion rescattering model for pion absorption in nuclei leads to a rapid increase with pion energy for the absorptive part of the $S$-wave pion-nucleus optical potential proportional to $p^2$. The energy dependence is almost entirely due to the pion-nucleon rescattering amplitude and not to nuclear structure effects.