Speaker
Toshiyuki Sumikama
(Tokyo University of Science)
Description
Shape evolution around 110Zr attracts much attention because shape transition from prolate to oblate, spherical or more exotic tetrahedral shapes has been predicted by many authors. 110Zr is expected to be a spherical shape due to a possible subshell closure at N=70 [1]. Furthermore, the transition to an oblate shape may appear in more neutron-rich region [2].
We performed the experiment around 110Zr with stopped beams as a first decay experiment at RIBF [3, 4, 5]. The observed low-lying states of 106, 108Zr indicate that these two nuclei are well deformed, and the deformation reaches maximum at N=64 by deformed subshell closure at N=64 [3]. By combining a higher intensity expected for 238U beam and a high-efficiency-gamma-ray array E(U)RICA, we will be able to approach more neutron-rich Zr and Mo isotopes around N=70. We also expect a detailed spectroscopy of the 108Zr isomer which is a candidate to search for the tetrahedral shape [3].
In this workshop, I will show the results of $^{106, 108}$Zr at the first decay experiment and a future plan of the decay experiment with EURICA around 110Zr.
[1] M. Bender et al., Phys. Rev. C 80, 064302 (2009).
[2] J. Skalski et al., Nucl. Phys,
[3] T. Sumikama et al., Phys. Rev. Lett. to be published.
[4] H. Watanabe et al., Phys. Lett. B 696, 186 (2011).
[5] S. Nishimura et al., Phys. Rev. Lett. 106, 052502 (2011).
Primary author
Toshiyuki Sumikama
(Tokyo University of Science)
