New insights into neutron-rich nuclei at high spinJ.H. Hamilton1, A.V. Ramayya1, J.K. Hwang1, X.Y. Luo1, J.O. Rasmussen2, E.F. Jones1, 3, X.Q. Zhang1, S.J. Zhu1, 4, 5, P.M. Gore1, T.N. Ginter2, I.Y. Lee2, R.V.F. Janssens6, I. Ahmed6, J.D. Cole1, 7, W. Greiner8, G. Ter-Akopian4, 9 and Yu. Oganessian9
1 Physics Department, Vanderbilt University, Nashville, TN 37235, USA
2 Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
3 Universidade de Coimbra, Coimbra, Portugal
4 Joint Institute for Heavy Ion Research, Oak Ridge, TN 37835, USA
5 Physics Department, Tsinghua University, Beijing, PRC
6 Argonne National Laboratory, Argonne, IL 60439, USA
7 Idaho National Environmental and Engineering Laboratory, Idaho Falls, ID 83415, USA
8 Institute of Theoretical Physics, Goethe University, Frankfurt am Main, Germany
9 Flerov Laboratory for Nuclear Reactions, JINR, Dubna, Russia
(Received: 21 March 2002 / Published online: 31 October 2002)
With new high statistic data, new isotopes and new high-spin structures are observed in neutron-rich nuclei populated in the spontaneous fission of 252Cf. The 135Te levels are extended, and many new levels in 139,141Ba observed. The coexistence of collective and single particle-hole states is found in 135Te. The N=83 135Te and 139Ba show marked differences associated with differences in their particle and hole states. New levels in 141Ba complete evidence for two opposite-parity doublets characteristic of stable octupole deformation. In 114,116Pd a second backbend is observed for the first time in this mass region and the backbend in 118Pd occurs earlier than in Pd because of a reduction in pairing. Gamma-type vibrational bands are seen up to 13 + to 15 + in 104,106Mo, Ru, and Pd. Their behavior reflects prolate to triaxial shapes in these nuclei. The levels of 162,164Gd are observed for the first time. As N increases toward mid-shell at 104, the moments of inertia in N=100 164Gd show an unexpected decrease compared to N=98 162Gd. The levels in 162,164Gd form remarkable shifted identical bands with nuclei separated by 2n, 2p, , and 2 .
25.85.Ca - Spontaneous fission.
27.60.+j - .
27.60.+q - .
21.60.-n - Nuclear-structure models and methods.
© Società Italiana di Fisica, Springer-Verlag 2002