Spin-dependent interactions play essential roles in nuclear structure and reactions. One of the best known examples is the spin asymmetry found in nucleon elastic scattering, which is a direct manifestation of the spin-orbit interaction. Since the spin-orbit interaction is expected to work in the surface region, it is natural to expect that such interaction could be strongly modified by the characteristic surface structure of neutron-skin or -halo nuclei.
At RIKEN RIBF, we have measured the proton elastic scattering from 6He at 200 A MeV utilizing a spin-polarized proton target specially developed for the RI-beam experiments. Recoil protons were detected with ESPRI Recoil Proton Spectrometer. Scattered particles were analyzed by the SAMURAI spectrometer.
The differential cross sections have been obtained in the highest momentum transfer region among the existing measurement, where the cross sections are dominated by the contribution of an alpha core. The data will be shown and compared with theoretical calculations assuming different radii of the core distribution. Preliminary results of the vector analyzing power will also be presented.