Covalent isomeric state in {sup 12}Be induced by two-neutron transfers
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, Wako, 351-0198 Saitama (Japan)
- Department of Physics, University of Tokyo, Hongo, 113-0033 Tokyo (Japan)
The {alpha}+{sup 8}He low-energy reactions and the exotic structures of {sup 12}Be are studied using the generalized two-center cluster ({alpha}+{alpha}+4N) model. In the two-neutron transfer reactions, {alpha}+{sup 8}He{sub g.s.}{yields}{sup 6}He{sub g.s.}+{sup 6}He{sub g.s.}, a resonant peak with J{sup {pi}}=0{sup +} appears around E {approx} 1.3 MeV above the {sup 6}He{sub g.s.}+{sup 6}He{sub g.s.} threshold as the result of the formation of the covalent superdeformation, which has a hybrid structure of covalent and ionic configurations for the valence neutrons. The covalent superdeformation gives rise to an isomeric state with a sharp width of {gamma}{approx}400 keV, which is smaller by about one order of magnitude than the typical width observed in molecular resonances above the Coulomb barrier. The energy-spin systematics for the two-neutron transfer reactions is investigated, and our calculation predicts a sequence of resonant structures in the range of 3-14 MeV in the center-of-mass energy with spins 0({Dirac_h}/2{pi})-8({Dirac_h}/2{pi})
- OSTI ID:
- 21192006
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 78, Issue 1; Other Information: DOI: 10.1103/PhysRevC.78.011602; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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