For nucleons scattered by odd-mass nuclei, a spin-spin interaction consisting of spherical and tensor terms is added to the optical potential. The effect of this interaction on the scattering amplitude is calculated using distorted-wave Born approximation. The shape and strength of the spherical term are based on an approximate microscopic treatment, while the tensor term is treated phenomenologically. Theoretical calculations are carried out for several observable quantities. The calculated depolarizations are compared with the limited data available for 50- and 20-MeV protons. Because of large uncertainties in the 50-MeV data it is not possible to clearly assess the role played by each of the spin-spin terms. However, for the 20-MeV data, the depolarizations calculated using the spherical term alone are found to be consistently different from the measured values. These suggest that contributions from the tensor term are important. The effects of the spin-spin interaction on the differential cross section, polarization, asymmetry, and rotation parameters are found to be small. It is shown that measurements of the angular distribution of the depolarization parameter could be useful in determining the strength of the tensor interaction.

• Received 3 April 1973

DOI:https://doi.org/10.1103/PhysRevC.8.518