Application of the Intermediate-Coupling Unified Nuclear Model to Odd-Mass Cesium Isotopes

Abstract

Experimental data on the properties of low-lying levels of the odd-mass cesium isotopes are investigated within the framework of the intermediate-coupling approach in the unified nuclear model. The calculations are performed by assuming that either the last odd proton having available to it several single-particle states, or the three-proton-hole state in the $1{g}_{\frac{7}{2}}$ subshell, which can undergo excitations, is coupled to the quadrupole vibrations of the surface of the appropriate doubly even core. Using reasonable values for the parameters involved, the calculated low-energy spectra of ${\mathrm{Cs}}^{131}$, ${\mathrm{Cs}}^{133}$, and ${\mathrm{Cs}}^{135}$ are in good agreement with experimental data. The wave functions obtained from our model are used to calculate the electromagnetic transition probabilities, lifetimes, and magnetic dipole and electric quadrupole moments for several of the low-lying levels in each of the nuclei considered. These, too, are found to be in substantial agreement with the available experimental data. The results of our calculations are also compared with other theoretical work available.