Effect of spin-spin interactions on nucleon-nucleus scattering

Abstract

We report on a model for determining spin-spin terms in the optical potential for elastic scattering of a nucleon from a target with nonzero spin. These terms are constructed microscopically by folding a realistic effective nucleon-nucleon interaction, which includes both direct and exchange parts, over the ground state of the target nucleus wave function to generate a nucleon-nucleus potential. The resulting spin-spin tensors are evaluated within DWBA. This general model has been used for the specific calculation of polarization transfer coefficient DNN, which is unity if there are no spin-spin terms in the optical potential. We have calculated DNN for the elastic scattering of 200 MeV protons from 10B, for which relevant experimental data exist. In our model, the folding formalism leads to both local and nonlocal spin-spin tensor interactions, with higher order couplings in the projectile and target spin that have not been explicitly considered before. We have found that the spin-spin interactions derived from this model have a significant effect on the deviation of DNN from unity, particularly those derived from the tensor exchange term in the NN interaction. The calculation of DNN has also been shown to be particularly sensitive to the parameters of the model used to describe the nuclear structure. © 2013 American Physical Society.