Multiple coulomb excitation experiment of Zn

Koizumi, Mitsuo ; Seki, Akiyuki*; Toh, Yosuke   ; Osa, Akihiko  ; Utsuno, Yutaka   ; Kimura, Atsushi   ; Oshima, Masumi; Hayakawa, Takehito; Hatsukawa, Yuichi; Katakura, Junichi; Matsuda, Makoto  ; Shizuma, Toshiyuki; Czosnyka, T.*; Sugawara, Masahiko*; Morikawa, Tsuneyasu*; Kusakari, Hideshige*

Coulomb excitation experiment was carried out with a Zn beam bombarding a Pb target. Two matrix elements and the quadrupole moment of the 2 state were newly derived with the least-squares search code GOSIA. The potential energy surface (PES) was calculated with the Nilsson-Strutinsky model, showing two shallow minima: the first minimum does not contain the orbit below the Fermi surface, while the second minimum does. The ground state band and the intruder band seem to be constructed on the first and the second minimum, respectively. As for the ground state band, the asymmetric rotor model and the IBM in O(6) limit reproduced the experimental values rather well. The shallow PES may suggest unstability of the shape. The ground state band structure may be explained assuming a soft triaxial deformation.