Speaker
Dr
T. Sumikama
(Tokyo University of Science)
Description
Neutron-rich Zr isotopes are suddenly deformed at N = 60 and quadrupole deformation $¥beta_2$ reaches around 0.4 [1]. While the deformed sub-shell closure is predicted at N = 60, 62, and 64 [2], the relation between the deformation evolution and the deformed sub-shell closure is unknown, because the deformation evolution beyond N = 64 has not been measured. In the present study, we measured the low-lying state energies of 106Zr and 108Zr to investigate the deformation evolution.
The secondary beam of the neutron-rich Zr and Y isotopes was produced as in-flight fission fragments of the 238U beam with 345 MeV/nucleon at RI Beam Factory, RIKEN. We measured the beta-delayed gamma rays from 106Y, which decays to 106Zr, and the gamma rays from a newly-discovered isomer of 108Zr. We will report on experimental results and discuss about the deformed sub-shell closure at N = 64, and also about a possibility of a tetrahedral shape isomer of 108Zr [3].
[1] ENSDF database, NNDC.
[2] J. Skalski, S. Miztori and W. Nazarewicz, Nucl. Phys. A 617, 282 (1997).
[3] T. Sumikama, et al., Phys. Rev. Lett. (to be published), arXiv:1104.2958.
Primary author
Dr
T. Sumikama
(Tokyo University of Science)
Co-authors
A. Bracco
(INFN, Sezione di Milano)
A. Odahara
(Osaka University)
A. Takashima
(Osaka University)
C. Hinke
(TU Munchen)
D. G. Jenkins
(University of York)
D. Steppenbeck
(RIKEN Nishina Center)
E. Ideguchi
(CNS, University of Tokyo)
F. Camera
(INFN, Sezione di Milano)
G. Lorusso
(RIKEN Nishina Center)
H. Baba
(RIKEN Nishina Center)
H. Sakurai
(RIKEN Nishina Center)
H. Scheit
(TU Darmstadt)
H. Watanabe
(RIKEN Nishina Center)
H. Yamaguchi
(CNS, University of Tokyo)
H.J. Ong
(Osaka University)
J. Chiba
(Tokyo University of Science)
J. S. Berryman
(Michigan State University)
K. Steiger
(TU Munchen)
K. Sugimoto
(Tokyo University of Science)
K. Tajiri
(Osaka University)
K. Yamaguchi
(Osaka University)
K. Yoshinaga
(Tokyo University of Science)
M. Kurata-Nichimura
(RIKEN Nishina Center)
N. Blasi
(INFN, Sezione di Milano)
N. Kobayashi
(Tokyo Institute of Technology)
O. Wieland
(INFN, Sezione di Milano)
P. Doornenbal
(RIKEN Nishina Center)
R. Krucken
(TU Munchen)
S. Go
(CNS, University of Tokyo)
S. Hayakawa
(CNS, University of Tokyo)
S. Kubono
(CNS, University of Tokyo)
S. Nishimura
(RIKEN Nishina Center)
S. Ota
(CNS, University of Tokyo)
S. Takano
(Tokyo University of Science)
T. Hashimoto
(CNS, University of Tokyo)
T. Isobe
(RIKEN Nishina Center)
T. Nakano
(Tokyo University of Science)
T. Teranishi
(Kyushu University)
Y. Ito
(Osaka University)
Y. Kawada
(Tokyo Institute of Technology)
Y. Kondo
(Tokyo Institute of Technology)
Y. Miyashita
(Tokyo University of Science)
Y. Wakabayashi
(JAEA)
Z. Li
(RIKEN Nishina Center)
Zs. Podolyak
(University of Surrey)
