Deformation of the nucleon and delta in excited states

A quark model for baryons, in which the valence quarks are moving in a deformable mean field, is considered. A q-q interaction, consisting of one-gluon-exchange and one-pion-exchange potentials, is diagonalized exactly in the model space of deformed orbitals. With four model parameters, the masses of both the even- and odd-parity states and the radiative transition amplitudes for the L=0 excited states are obtained in fair agreement with experiment