Quadrupole deformation of 12Be studied by proton inelastic scattering

Abstract Inelastic proton scattering exciting the 2 + 1 states in the neutron-rich beryllium isotopes 10,12 Be has been studied in inverse kinematics. From a coupled-channel analysis, the deformation lengths for the 2 + 1 states in 10 Be and 12 Be were determined to be 1.80±0.25 fm and 2.00±0.23 fm respectively, indicating that a tendency towards strong quadrupole deformation is preserved for these nuclei and that the singly-closed shell structure does not prevail in 12 Be. A quantitative analysis based on shell model calculations supports this picture.