Microscopic aspects of $\gamma$-softness in atomic nuclei

Abstract

The microscopic origin of the $\gamma$-softness (fluctuations in the triaxiality parameter $\gamma$ of the nuclear shape) observed in atomic nuclei is studied in the framework of the triaxial projected shell model approach, which is based on the deformed mean-field picture with multi-quasiparticle configuration space. It is demonstrated that the coupling to quasiparticle excitations drives the system from a $\gamma$-rigid to a $\gamma$-soft pattern. As an illustrative example for a $\gamma$-soft nucleus, a detailed study has been performed for the ${}^{104}$Ru nucleus. The experimental energies and a large sample of measured $E2$ matrix elements available for this nucleus are reproduced quite accurately. The shape invariant analysis of the calculated $E2$ matrix elements elucidates the $\gamma$-soft nature of ${}^{104}$Ru.

References in corpus (10)

• Relativistic Nuclear Energy Density Functionals: Mean-Field and Beyond
• Quantum Phase Transition in the Shape of Zr isotopes
• Triaxial projected shell model approach
• Shell Model Monte Carlo Studies of $\gamma$-Soft Nuclei
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• The low-lying quadrupole collective excitations of Ru and Pd isotopes
• The Low-Energy Quadrupole Mode of Nuclei
• Microscopic Calculation of IBM Parameters by Potential Energy Surface Mapping
• Intrinsic properties of high-spin band structures in triaxial nuclei
• Systematic study of near yrast band structures in odd-mass ${}^{125-137}$Pr and ${}^{127-139}$Pm isotopes