Structure of 12Be: intruder d-wave strength at N=8.
/ Authors
S. Pain, W. Catford, N. Orr, J. Angelique, N. Ashwood, V. Bouchat, N. Clarke, N. Curtis, M. Freer, B. Fulton
and 20 more authors
F. Hanappe, M. Labiche, J. Lecouey, R. Lemmon, D. Mahboub, A. Ninane, G. Normand, N. Soiċ, L. Stuttgé, C. Timis, J. Tostevin, J. Winfield, V. Z. .. U. O. Surrey, Lpc Caen. University of Birmingham, Universit́e Libre de Bruxelles, U. York, University of Paisley, Cclrc Daresbury Laboratory, Universit'e catholique de Louvain, IResS Strasbourg
/ Abstract
The breaking of the N=8 shell-model magic number in the 12Be ground state has been determined to include significant occupancy of the intruder d-wave orbital. This is in marked contrast with all other N=8 isotones, both more and less exotic than 12Be. The occupancies of the [FORMULA: SEE TEXT]orbital and the [FORMULA: SEE TEXT], intruder orbital were deduced from a measurement of neutron removal from a high-energy 12Be beam leading to bound and unbound states in 11Be.
Journal: Physical review letters