Theoretical Study on Rotational Bands and Shape Coexistence of $^{183,185,187}${Tl} in the Particle Triaxial-Rotor Model

Abstract

By taking the particle triaxial-rotor model with variable moment of inertia, we investigate the energy spectra, the deformations and the single particle configurations of the nuclei $^{183,185,187}$Tl systemically. The calculated energy spectra agree with experimental data quite well. The obtained results indicate that the aligned bands observed in $^{183,185,187}$Tl originate from the $[530]{1/2}^{-}$, $[532]{3/2}^{-}$, $[660]{1/2}^{+}$ proton configuration coupled to a prolate deformed core, respectively. Whereas, the negative parity bands built upon the ${9/2}^{-}$ isomeric states in $^{183,185,187}$Tl are formed by a proton with the $[505]{9/2}^{-}$ configuration coupled to a core with triaxial oblate deformation, and the positive parity band on the ${13/2}^{+}$ isomeric state in $^{187}$Tl is generated by a proton with configuration $[606]{13/2}^{+}$ coupled to a triaxial oblate core.