Bag model with residual interaction for the quarks

We propose a modified version of the MIT bag in which the quarks are subject to a central potential. As in other models, the continuity of the axial current is assured by introducing a pionic cloud surrounding the bag, but it is no longer necessary to allow the pion field to penetrate the bag to obtain reasonable values of the axial charge, the magnetic moment and the charge radius of the nucleon. The magnetic moments of the hyperons are also well described. (orig.)