DOI: 10.1140/epja/i2001-10249-1
New insights into neutron-rich nuclei at high spin
J.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. Oganessian91 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
j.h.hamilton@vanderbilt.edu
(Received: 21 March 2002 / Published online: 31 October 2002)
Abstract
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
