The first 2+ state of 14Be

The first excited state of the most neutron-rich beryllium isotope, 14Be, has been studied by inelastic scattering with a 12C target at 68MeV/nucleon. The state has been observed at Ex=1.54(13)MeV, and its spin-parity has been determined as Jπ=2+ from the measurement of the angular distribution. This provides a complete set of energies of the first 2+ states in the beryllium isotopic chain. The extracted deformation length of 14Be has been found to be substantially smaller than that of the neighboring nucleus 12Be, in which the N=8 shell closure is quenched, indicating hindered collectivity in the 14Be nucleus.