Study of the deformation-driving d 5/2 orbital in 67Ni using one-neutron transfer reactions

Phys. Lett. B

736
533
(2014)
J. Diriken, N. Patronis, A.N. Andreyev, S. Antalic, V. Bildstein, A. Blazhev, I.G. Darby, H. De Witte, J. Eberth, J. Elseviers, V.N. Fedosseev, F. Flavigny, Ch. Fransen, G. Georgiev, R. Gernhäuser, H. Hess, M. Huyse, J. Jolie, Th. Kröll, R. Krücken, R. Lutter, B.A. Marsh, T. Mertzimekis, D. Mücher, F. Nowacki, R. Orlandi, A. Pakou, R. Raabe, G. Randisi , P. Reiter, T. Roger, M. Seidlitz, M. Seliverstov, K. Sieja, C. Sotty, H. Tornqvist, J. Van De Walle, P. Van Duppen, D. Voulot, N. Warr, F. Wenander, K. Wimmer

The 
𝜈
g
9
/
2
,
d
5
/
2
,
s
1
/
2
 orbitals are assumed to be responsible for the swift onset of collectivity observed in the region below 68Ni. Especially the single-particle energies and strengths of these orbitals are of importance. We studied such properties in the nearby 67Ni nucleus, by performing a 
(
𝑑
,
𝑝
)
-experiment in inverse kinematics employing a post-accelerated radioactive ion beam (RIB) at the REX-ISOLDE facility. The experiment was performed at an energy of 2.95 MeV/u using a combination of the T-REX particle detectors, the Miniball γ-detection array and a newly-developed delayed-correlation technique as to investigate μs-isomers. Angular distributions of the ground state and multiple excited states in 67Ni were obtained and compared with DWBA cross-section calculations, leading to the identification of positive-parity states with substantial 
𝜈
g
9
/
2
 (1007 keV) and 
𝜈
d
5
/
2
 (2207 keV and 3277 keV) single-particle strengths up to an excitation energy of 5.8 MeV. 50% of the 
𝜈
d
5
/
2
 single-particle strength relative to the 
𝜈
g
9
/
2
-orbital is concentrated in and shared between the first two observed 
5
/
2
+
 levels. A comparison with extended Shell Model calculations and equivalent (3He, d) studies in the region around 9040Zr50 highlights similarities for the strength of the negative-parity pf and positive-parity 
g
9
/
2
 state, but differences are observed for the 
d
5
/
2
 single-particle strength.

DOI
10.1016/j.physletb.2014.08.004
Published on
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