Dynamic polarization potentials for the halo nucleus He6 in medium-energy elastic scattering

Abstract

We study dynamic polarization potentials for a halo nucleus $^{6}\mathrm{He}$ scattered by a $^{12}\mathrm{C}$ target in the eikonal approximation. We use a realistic, six-nucleon wave function of $^{6}\mathrm{He}$ to include both the halo-neutron and the core-nucleon excitations on an equal footing. We discuss the energy dependence of the polarization potential in relation to that of the nucleon-target optical potential. The imaginary part of the polarization potential changes a sign (negative to positive with increasing energy) around the incident energy of $200\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}∕\mathrm{nucleon}$, which gives different contributions, depending on the energy, to the elastic differential cross section as well as the reaction cross section.