Enhanced Core Polarization in {sup 70}Ni and {sup 74}Zn
- Institut de Physique Nucleaire, IN2P3-CNRS, F-91406 Orsay Cedex (France)
- CEA-Saclay, DAPNIA-SPhN, F-91191 Gif sur Yvette Cedex (France)
- CEA/DIF/DPTA/SPN, B.P. 12, F-91680 Bruyeres le Chatel (France)
- Nuclear Physics Institute, AS CR, CZ 25068, Rez (Czech Republic)
The reduced transition probabilities B(E2;0{sup +}{yields}2{sub 1}{sup +}) of the neutron-rich {sup 74}Zn and {sup 70}Ni nuclei have been measured by Coulomb excitation in a {sup 208}Pb target at intermediate energy. These nuclei have been produced at Grand Accelerateur National d'Ions Lourds via interactions of a 60A MeV {sup 76}Ge beam with a Be target. The B(E2) value for {sup 70}Ni{sub 42} is unexpectedly large, which indicates that neutrons added above N=40 strongly polarize the Z=28 proton core. In the Zn isotopic chain, the steep rise of B(E2) values beyond N=40 continues up to {sup 74}Zn{sub 44}. The enhanced proton core polarization in {sup 70}Ni is attributed to the monopole interaction between the neutron in the g{sub 9/2} and protons in the f{sub 7/2} and f{sub 5/2} spin-orbit partner orbitals. This interaction could result in a weakening of magicity in {sup 78}Ni{sub 50}.
- OSTI ID:
- 20777284
- Journal Information:
- Physical Review Letters, Vol. 96, Issue 23; Other Information: DOI: 10.1103/PhysRevLett.96.232501; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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