CXII. Spin-orbit coupling and the density distribution in heavy nuclei

Abstract The spin-orbit coupling experienced by a nucleon in a nucleus is interpreted in terms of a neutral two-body spin-orbit potential. An expression of the Thomas form is obtained for the effective spin-orbit potential. It is shown that the spin-orbit splitting in heavy nuclei can be explained satisfactorily if the nuclear density distribution has a finite transition region at the surface and if the neutron distribution has a larger radius than the proton distribution.