The coherent-state model is extended to the description of the proton-neutron systems. Three (p,n) symmetric bands (g, β, and γ̃) and three asymmetric bands (γ, $1^{+}$, 1${̃}^{+}$) are simultaneously considered. Their wave functions are obtained through projection from six deformed states which are mutually orthogonal. An effective quadrupole boson Hamiltonian which is diagonal in the projected basis is constructed. Applications to ${}_{}{}^{156}{}_{}{}^{}$,158,160Gd show very good agreement with the experimental data concerning the g, β, and γ bands and the $1^{+}$ isovector state. Predictions for two additional bands, one with K=2(γ̃) and one with K=1(1${̃}^{+}$), are also presented. A detailed analysis for the electromagnetic properties of the $1^{+}$ M1 state is given.

• Received 28 May 1986

DOI:https://doi.org/10.1103/PhysRevC.36.2111