Inelastic scattering of the neutron-rich nucleus 12Be on lead and carbon targets has been studied by measuring de-excitation γ rays in coincidence with scattered 12Be. The strong γ-ray transition from the state at E(x) = 2.68(3) MeV following El Coulomb excitation was observed for the lead target, leading to an assignment of J(π) = I- for the excited state. The low excitation energy of this intruder 1- state and the deduced large B(E1; 0(g.s.)/+ → 1-) value of 0.051 (13)e2 fm2 provide a consistent picture o the N = 8 shell melting in 12Be. (C) 2000 Elsevier Science B.V.
|Number of pages||7|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 2000 Oct 12|