Type II shell evolution in A=70 isobars from the N >= 40 island of inversion


MORALES A. I. , BENZONI G., WATANABE H., TSUNODA Y., OTSUKA T., NISHIMURA S., ...Daha Fazla

PHYSICS LETTERS B, cilt.765, ss.328-333, 2017 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 765
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1016/j.physletb.2016.12.025
  • Dergi Adı: PHYSICS LETTERS B
  • Sayfa Sayıları: ss.328-333

Özet

The level structures of Co-70 and Ni-70, populated from the Chi decay of Fe-70, have been investigated using beta-delayed gamma-ray spectroscopy following in-flight fission of a U-238 beam. The experimental results are compared to Monte-Carlo Shell-Model calculations including the pf + g(9/2) + d(5/2) orbitals. The strong population of a (1(+)) state at 274 keV in Co-70 is at variance with the expected excitation energy of 1 MeV from near spherical single-particle estimates. This observation indicates a dominance of prolate deformed intruder configurations in the low-lying levels, which coexist with the normal near spherical states. It is shown that the 13 decay of the neutron-rich A = 70 isobars from the new island of inversion to the Z = 28 closed-shell regime progresses in accordance with a newly reported type of shell evolution, the so-called Type II, which involves many particle-hole excitations across energy gaps. (C) 2016 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license.