The role of spin-unsaturated subshells in calculations of optical-model spin-orbit potentials is investigated using a realistic nucleon-nucleon interaction. For projectiles of moderate bombarding energies the one-body spin-orbit potential is predicted to be quenched relative to that for nearby nuclei having only spin-saturated shells. The source of this quenching is the same as that discussed by Scheerbaum in an investigation of the quenching of spin-orbit splittings in bound states. A simple physical picture is given which permits a qualitative understanding of this quenching in terms of the components of the nucleon-nucleon interaction. An estimate of the effect on polarization-like observables is made, and a general problem with currently used tensor forces is reemphasized. The relationship of this problem to a number of other structure and scattering problems is stressed.

NUCLEAR REACTIONS, NUCLEAR STRUCTURE Calculation of contributions to the optical-model spin-orbit potential from spin-unsaturated subshells.

• Received 15 January 1979

DOI:https://doi.org/10.1103/PhysRevC.20.1638