Single-neutron knockout from intermediate energy beams of {sup 30,32}Mg: Mapping the transition into the 'island of inversion'

Journal Article · Tue Jan 15 04:00:00 EST 2008 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.77.014316· OSTI ID:21068050

Terry, J R; Brown, B A; Campbell, C M; Cook, J M; Davies, A D; Dinca, D -C; Gade, A; Glasmacher, T; Hansen, P G; Sherrill, B M; Zwahlen, H; Bazin, D; Yoneda, K; Tostevin, J A; Otsuka, T; Utsuno, Y; Pritychenko, B ^[1]

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1. National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States)

The breakdown of the N=20 magic number in the so-called island of inversion around {sup 32}Mg is well established. Recently developed large-scale shell-model calculations suggest a transitional region between normal- and intruder-dominated nuclear ground states, thus modifying the boundary of the island of inversion. In particular, a dramatic change in single-particle structure is predicted between the ground states of {sup 30}Mg and {sup 32}Mg, with the latter consisting nearly purely of 2p-2h N=20 cross-shell configurations. Single-neutron knockout experiments on {sup 30,32}Mg projectiles have been performed. We report on a first direct observation of intruder configurations in the ground states of these very neutron-rich nuclei. Spectroscopic factors to low-lying negative-parity states in the knockout residues are deduced and compare well with shell-model predictions.

• OSTI ID: 21068050
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 1 Vol. 77; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
COMPARATIVE EVALUATIONS
GROUND STATES
KNOCK-OUT REACTIONS
MAGNESIUM 30
MAGNESIUM 32
NEUTRON-RICH ISOTOPES
NEUTRONS
NITROGEN 20
NUCLEAR STRUCTURE
PARITY
SHELL MODELS
SINGLE-PARTICLE MODEL
SPECTROSCOPIC FACTORS