Coulomb Excitation of Neutron-Rich Zn Isotopes: First Observation of the 2+1 State in 80Zn

Phys. Rev. Lett.

99
142501
(2007)
J. Van de Walle, F. Aksouh, F. Ames, T. Behrens, V. Bildstein, A. Blazhev, J. Cederkäll, E. Clément, T.E. Cocolios, T. Davinson, P. Delahaye, J. Eberth, A. Ekström, D.V. Fedorov, V.N. Fedosseev, L.M. Fraile, S. Franchoo, R. Gernhäuser, G. Georgiev, D. Habs, K. Heyde, G. Huber, M. Huyse, F. Ibrahim, O. Ivanov, J. Iwanicki, J. Jolie, O. Kester, U. Köster, T. Kröll, R. Krücken, M. Lauer, A.F. Lisetskiy, R. Lutter, B.A. Marsh, P. Mayet, O. Niedermaier, T. Nilsson, M. Pantea, O. Perru, R. Raabe, P. Reiter, M. Sawicka, H. Scheit, G. Schrieder, D. Schwalm, M.D. Seliverstov, T. Sieber, G. Sletten, N. Smirnova, M. Stanoiu, I. Stefanescu, J.-C. Thomas, J.J. Valiente-Dobon, P. Van Duppen, D. Verney, D. Voulot, N. Warr, D. Weißhaar, F. Wenander, B.H. Wolf, M. Zielińska

Neutron-rich, radioactive Zn isotopes were investigated at the Radioactive Ion Beam facility REX-ISOLDE (CERN) using low-energy Coulomb excitation. The energy of the 2+
1 state in  
78
 Zn 
  could be firmly established and for the first time the 2+ →0+
1 transition in  
80
 Zn 
  was observed at 1492(1) keV. 𝐵⁡(𝐸⁢2,2+
1 →0+
1) values were extracted for  
74,76,78,80
 Zn 
  and compared to large scale shell model calculations. With only two protons outside the 𝑍 =28 proton core,  
80
 Zn 
  is the lightest 𝑁 =50 isotone for which spectroscopic information has been obtained to date. Two sets of advanced shell model calculations reproduce the observed 𝐵⁡(𝐸⁢2) systematics. The results for 𝑁 =50 isotones indicate a good 𝑁 =50 shell closure and a strong 𝑍 =28 proton core polarization. The new results serve as benchmarks to establish theoretical models, predicting the nuclear properties of the doubly magic nucleus  
78
 Ni 
 .

DOI
10.1103/PhysRevLett.99.142501
Published on
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