Low-energyp+He3elastic scattering and the optical potential

It is shown that the optical model potential with central, spin-orbit, and exchange terms can provide reasonably good fits to the cross section, polarization, and the polarization transfer coefficients $K_x^{x^{\prime }}$ and $K_z^{x^{\prime }}$ for $p$+${}_{}{}^3{}_{}{}^{}\mathrm{He}$ elastic scattering in the energy range 6.8-16.2 MeV. The measured values of the polarization transfer coefficient $K_y^{y^{\prime }}$ are compared with those calculated by adding a spherical spin-spin interaction term to the potential. Both phenomenological and folding-model spin-spin terms are considered. Good agreement is obtained for the 16.2 MeV data but not for the data at lower energies. The effects of including a tensor spin-spin interaction are also studied.