Shape coexistence and triaxiality in nuclei near 80Zr.

Total-Routhian-surface calculations have been performed to investigate the shape evolutions of A~80 nuclei: 80-84Zr, 76-80Sr, and 84,86Mo. Shape coexistences of spherical, prolate, and oblate deformations have been found in these nuclei. Particularly for the nuclei 80Sr and 82Zr, the energy differences between two shape-coexisting states are less than 220 keV. At high spins, the g9/2 shell plays an important role in shape evolutions. It has been found that the alignment of the g9/2 quasiparticles drives nuclei to be triaxial. [ABSTRACT FROM AUTHOR]