Exploring the "Island of Inversion" by in-beam gamma-ray spectroscopy of the neutron-rich sodium isotopes 31,32,33Na

Abstract

The structure of the neutron rich sodium isotopes 31,32,33Na was investigated by means of in-beam gammaray spectroscopy following one-neutron knockout and inelastic scattering of radioactive beams provided by the RIKEN Radioactive Ion Beam Factory. The secondary beams were selected and separated by the fragment separator BigRIPS and incident at ~240 meV/u on a natural carbon (secondary) target, which was surrounded by the DALI2 array to detect coincident de-excitation gammarays. Scattered particles were identified by the spectrometer ZeroDegree. In 31Na, a new decay gammaray was observed in coincidence with the known (5/2+)-> 3/2(+) transition, while for 32,33Na excited states are reported for the first time. From a comparison to state-of-the-art shell model calculations it is concluded that the newly observed excited state in 31Na belongs to a rotational band formed by a 2p2h intruder configuration within the "Island of Inversion".

arXiv commentAccepted for Publication in Phys. Rev. C, 11 pages, 6 figures

References in corpus (4)

• Magic numbers in exotic nuclei and spin-isospin properties of {\it NN} interaction
• Spectroscopy of 32Ne and the Island of Inversion
• Shell model studies of neutron rich nuclei
• 29Na: Defining the edge of the Island of Inversion for Z=11

Cited by in corpus (8)

• Saturation with chiral interactions and consequences for finite nuclei
• DALI2: A NaI(Tl) detector array for measurements of $\gamma$ rays from fast nuclei
• The merging of the islands of inversion at N=20 and N=28
• Exploring sd-shell nuclei from two- and three-nucleon interactions with realistic saturation properties
• The Neutron-Rich Edge of the Nuclear Landscape. Experiment and Theory
• In-beam gamma-ray spectroscopy of 35Mg and 33Na
• Effect of channel coupling on the elastic scattering of lithium isotopes
• Ab initio nuclear shape coexistence and emergence of island of inversion around $N=20$