Description of the Rigid Triaxial Deformation at Low Energy in ⁷⁶Ge with the Proton-Neutron Interacting Model IBM2

We investigate properties of the low-lying energy states for ⁷⁶Ge within the framework of the proton-neutron interacting model IBM2, considering the validity of the Z=38 subshell closure ⁸⁸Sr₅₀ as a doubly magic core. By introducing the quadrupole interactions among like bosons to the IBM2 Hamiltonian, the energy levels for both the ground state and γ bands are reproduced well. Particularly, the doublet structure of the γ band and the energy staggering signature fit the experimental data correctly. The ratios of B(E2) transition strengths for some states of the γ band, and the g factors of the 2⁺₁, 2⁺₂ states are very close to the experimental data. The calculation result indicates that the nucleus exhibiting rigid triaxial deformation in the low-lying states can be described rather well by the IBM2.