Pion-nucleon scattering lengths in the cloudy bag model

Abstract We reexamine pion-nucleon s-wave scattering in the volume coupling version of the CBM. If the effects of multiple scattering are taken into account, one needs some phenomological repulsive interaction in order to reproduce the experimental interaction in order to reproduce the experimental data. We parametrize this repulsion as a twenty percent increase in the pion massinside the bag. It is argued that this relatively small change in mass provides strong, a posteriori support for the original assumptions of the CBM.