Quantum Phase Transition in the Shape of Zr isotopes.
The rapid shape change in Zr isotopes near neutron number N=60 is identified to be caused by type II shell evolution associated with massive proton excitations to its 0g_{9/2} orbit, and is shown to be a quantum phase transition. Monte Carlo shell-model calculations are carried out for Zr isotopes of N=50-70 with many configurations spanned by eight proton orbits and eight neutron orbits. Energy levels and B(E2) values are obtained within a single framework in good agreement with experiment, depicting various shapes in going from N=50 to 70. The novel coexistence of prolate and triaxial shapes is suggested.
Center for Nuclear Study, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Tomoaki
T
Togashi
Center for Nuclear Study, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Yusuke
Y
Tsunoda
Center for Nuclear Study, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.|Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.|National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.|Instituut voor Kern- en Stralingsfysica, KU Leuven, B-3001 Leuven, Belgium.
Takaharu
T
Otsuka
Center for Nuclear Study, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Noritaka
N
Shimizu