Triaxial Shapes in the Interacting Vector Boson Model

Abstract

A new dynamical symmetry limit of the two-fluid Interacting Vector Boson Model (IVBM), defined through the chain $Sp(12,R)\supset U(3,3)\supset U^{\ast }(3)\otimes SU(1,1)\supset S{U}^{\ast }(3)\supset SO(3)$, is introduced. The $S{U}^{\ast }(3)$ algebra considered in the present paper closely resembles many properties of the $S{U}^{\ast }(3)$ limit of IBM-2, which have been shown by many authors geometrically to correspond to the rigid triaxial model. The influence of different types of perturbations on the $S{U}^{\ast }(3)$ energy surface, in particular the addition of a Majorana interaction and an O(6) term to the model Hamiltonian, is studied. The effect of these perturbations results in the formation of a stable triaxial minimum in the energy surface of the IVBM Hamiltonian under consideration. Using a schematic Hamiltonian which possesses a perturbed $S{U}^{\ast }(3)$ dynamical symmetry, the theory is applied for the calculation of the low-lying energy spectrum of the nucleus ${}^{192}$Os. The theoretical results obtained agree reasonably with the experimental data and show a very shallow triaxial minimum in the energy surface for the ground state in ${}^{192}$Os, suggesting that the newly proposed dynamical symmetry might be appropriate for the description of the collective properties of different nuclei, exhibiting triaxial features.

10 pages, 9 figures

References in corpus (7)

• Quantum phase transitions in the interacting boson model
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• Bohr Hamiltonian with Davidson potential for triaxial nuclei
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Cited by in corpus (1)

• Axial asymmetry in the IVBM