Convection currents in nuclei in a relativistic mean-field theory

Isoscalar convection currents for nuclei with one valence particle or hole outside a closed-shell core are studied in the mean-field (Hartree) approximation to the Walecka model. The currents are constructed using nucleon wave functions computed in the self-consistent potentials of the spherical core. Approximate self-consistency for the full odd-A nucleus is imposed by using linear response theory to correct the core wave functions for the effects of the valence nucleon. At low q, this core response cancels the enhancement of the isoscalar current that arises from the reduced effective mass of the valence nucleon so that magnetic moments are close to the Schmidt predictions. In contrast, particle-hole mixing in the core response enhances the single-particle current further at higher q. Calculations of magnetic moments and elastic magnetic scattering in light nuclei are presented to illustrate these results. The relationship of these calculations to fully self-consistent mean-field solutions of odd-A nuclei and to the linear response function in nuclear matter is discussed.