Speaker
Kenta Yoshinaga
(Tokyo University of Science)
Description
A drastic shape evolution is predicted in neutron-rich nuclei around A=110 [1].
For the Zr isotopes, a deformation may reach a maximum by a deformed shell-closure.
Energies of low-lying states which are known up to N=64 show the increase of the deformation from N=60 to 64.
However, the maximization of the deformation has not been observed as a function of neutron numbers.
Furthermore, a spherical shape may appear around 110Zr due to a possible sub-shell closure at N=70 [2].
For neutron-rich isotopes with Z > 40, a shape transition from prolate to oblate shapes is predicted around A=110 [1] and an oblate-shape isomer may appear.
In addition, beta-decay half-lives of this neutron-rich region are required to study the r-process nucleosynthesis.
We performed a first beta-gamma spectroscopy experiment with stopped beams at RIBF for neutron-rich A~110 nuclei.
In this workshop, I'll show an experimental overview and first results related to the shape evolution of the Zr and Nb isotopes [3,4], and beta-decay half-lives [5].
[1] J. Skalski et al., Nucl. Phys. A 617, 282 (1997).
[2] M. Bender et al., Phys. Rev. C 80, 064302 (2009).
[3] T. Sumikama et al., Phys. Rev. Lett. to be published.
[5] H. Watanabe et al., Phys. Lett. B 696, 186 (2011).
[4] S. Nishimura et al., Phys. Rev. Lett. 106, 052502 (2011).
Primary author
Kenta Yoshinaga
(Tokyo University of Science)
Co-author
Toshiyuki Sumikama
(Tokyo University of Science)
