97Rb - the cornerstone of the region of deformation around A ~ 100

Phys. Rev. Lett.

115
172501
(2015)
C. Sotty, M. Zielińska, G. Georgiev, D. L. Balabanski, A. E. Stuchbery, A. Blazhev, N. Bree, R. Chevrier, S. Das Gupta, J. M. Daugas, T. Davinson, H. De Witte, J. Diriken, L. P. Gaffney, K. Geibel, K. Hadyńska-Klȩk, F. G. Kondev, J. Konki, T. Kröll, P. Morel, P. Napiorkowski, J. Pakarinen, P. Reiter, M. Scheck, M. Seidlitz, B. Siebeck, G. Simpson, H. Tornqvist, N. Warr, F. Wenander

Excited states of the neutron-rich nuclei  
97,99
 Rb 
  were populated for the first time using the multistep Coulomb excitation of radioactive beams. Comparisons of the results with particle-rotor model calculations provide clear identification for the ground-state rotational band of  
97
 Rb 
  as being built on the 𝜋⁢𝑔9/2 [431] 3/2+ Nilsson-model configuration. The ground-state excitation spectra of the Rb isotopes show a marked distinction between single-particle-like structures below 𝑁 =60 and rotational bands above. The present study defines the limits of the deformed region around 𝐴 ∼100 and indicates that the deformation of  
97
 Rb 
  is essentially the same as that observed well inside the deformed region. It further highlights the power of the Coulomb-excitation technique for obtaining spectroscopic information far from stability. The  
99
 Rb 
  case demonstrates the challenges of studies with very short-lived postaccelerated radioactive beams.

DOI
10.1103/PhysRevLett.115.172501
Published on
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