The first 2 + state of 14Be
Abstract
The first excited state of the most neutron-rich beryllium isotope, 14Be, has been studied by inelastic scattering with a 12C target at 68 MeV /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.
- Publication:
-
Physics Letters B
- Pub Date:
- October 2007
- DOI:
- 10.1016/j.physletb.2007.08.052
- Bibcode:
- 2007PhLB..654..160S
- Keywords:
-
- Drip-line nucleus;
- Shell evolution;
- Collectivity;
- 21.10.-k;
- 27.20.+n;
- 21.10.Re;
- 21.10.Hw;
- Properties of nuclei;
- nuclear energy levels;
- 6<
- =A<
- =19;
- Collective levels;
- Spin parity and isobaric spin