Monte-Carlo shell model calculations of triaxially deformed states around134Ba

The nuclear structure of ground states and low-lying excited states of even-even isotopes around 134Ba is described using the nuclear shell model microscopically. These structures are revealed to show various phenomena of quadrupole collective states, including the transition of spherical, axially symmetric deformed and triaxially deformed shapes and the realization of the critical point symmetry, E(5).