Cross-shell excitations in 30Al and 30Si at high spin

✍ Scribed by D. Steppenbeck; A.N. Deacon; S.J. Freeman; R.V.F. Janssens; M.P. Carpenter; C.R. Hoffman; B.P. Kay; T. Lauritsen; C.J. Lister; D. O'Donnell; J. Ollier; D. Seweryniak; J.F. Smith; K.-M. Spohr; S.L. Tabor; V. Tripathi; P.T. Wady; S. Zhu

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 488 KB
• Volume: 847
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/j.nuclphysa.2010.07.010

✦ Synopsis

Yrast and near-yrast states in 30 Al and 30 Si have been populated to high spin with the 18 O + 14 C fusionevaporation reaction in inverse kinematics. The level schemes for these two isobars have been extended up to J ∼ 9 h at 9.4 and 15.5 MeV, respectively. Their decay schemes indicate that cross-shell excitations dominate at high spin, where negative-parity structures exist. Positive-parity states are compared to the results of shell-model calculations using the USD, USDA, and USDB effective interactions. The negative-parity levels are compared to predictions of the WBP interaction and the recently-developed WBP-a Hamiltonian, by allowing 1p-1h excitations to fp-shell orbitals. The results suggest that single-neutron excitations to the 0f 7/2 orbital play a significant role at high spin.