Early Onset of Ground State Deformation in Neutron Deficient Polonium Isotopes

T. E. Cocolios (1) , W. Dexters (1) , M. D. Seliverstov (1) , A. N. Andreyev (1) , S. Antalic , A. E. Barzakh , B. Bastin (1) , J. Bücher , I. G. Darby , D.V. Fedorov (2) , V. N. Fedosseyev , K. T. Flanagan (3) , S. Franchoo (4) , S. Fritzsche (5) , G. Huber , M. Huyse (1) , M. Keupers , U. Köster (6) , Yu. Kudryavtsev , E. Mané , B. A. Marsh , P. L. Molkanov , R. D. Page , A. M. Sjoedin , I. Stefan (4) , J. van de Walle , P. van Duppen (1) , M. Venhart (1) , S. G. Zemlyanoy , M. Bender (7) , P.-H. Heenen

1 IKS - Instituut voor Kern-en Stralingsfysica
2 Petersburg Nuclear Physics Institute
3 CSNSM SNO
4 IPNO - Institut de Physique Nucléaire d'Orsay
5 GSI - Helmholtz zentrum für Schwerionenforschung GmbH
6 ILL - Institut Laue-Langevin
7 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan

In-source resonant ionization laser spectroscopy of the even-A polonium isotopes 192-210;216;218Po has been performed using the 6p37s 5S2 to 6p37p 5P2 ( ¼ 843:38 nm) transition in the polonium atom (Po-I) at the CERN ISOLDE facility. The comparison of the measured isotope shifts in 200-210Po with a previous data set allows us to test for the first time recent large-scale atomic calculations that are essential to extract the changes in the mean-square charge radius of the atomic nucleus. When going to lighter masses, a surprisingly large and early departure from sphericity is observed, which is only partly reproduced by beyond mean field calculations.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

T. E. Cocolios, W. Dexters, M. D. Seliverstov, A. N. Andreyev, S. Antalic, et al.. Early Onset of Ground State Deformation in Neutron Deficient Polonium Isotopes. Physical Review Letters, 2011, 106, pp.052503. ⟨10.1103/PhysRevLett.106.052503⟩. ⟨in2p3-00576005⟩