Distinction between Proton-Neutron Density Distribution of Halo Nuclei at the Nuclear Surface via Reaction Cross Sections Original Research Article

Reaction cross sections (σR) for 11Be and 8B on proton targets at 50A∼120AMeV have been measured to distinguish between the proton- and neutron- density distributions at the nuclear surface. The σR is connected with the nucleon density distributions by the Glauber theory. Since the nucleon-nucleon total cross sections in that energy region have a large isospin dependence, the σR on proton targets should have a large difference between the proton and neutron in the halo structure. The experimental σR on proton targets are in good agreement with the calculated ones assuming that the tail dominantly consists of a neutron for 11Be and a proton for 8B.