Xue Shang | Searcharxiv

arXiv2026

Rigid triaxiality has the SU(3) symmetry: $^{166}$Er as an example

The emergence of triaxiality in the low-lying collective bands of $^{166}$Er is systematically explored within the SU3-IBM. In this framework, SU(3) higher-order interactions are included, which enable the descriptions of various quadrupole deformations. The triaxiality of $^{166}$Er is described with a triaxiality angle $\gamma=9.7^{\circ}$. In addition, the calculated energy spectra, $B(E2)$ transition strengths, and quadrupole moments show excellent agreement with experimental data. These results provide further evidence supporting the SU(3) triaxial interpretation of $^{166}$Er and confirm its triaxial deformation rather than the prolate shape.

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arXiv2025

SU(3) rigid triaxiality in $^{154}$Sm

The $^{154}$Sm nucleus, which has long been regarded as a typical quantum system exhibiting axial symmetry, has been recently suggested to exhibit a small degree of triaxiality by Otsuka \textit{et al.}. This small triaxiality was recently observed using the $\gamma$ decay of the $^{154}$Sm isovector giant dipole resonance. Thus further studying this small triaxiality is very necessary for understanding the nature of the collectivity in nuclei. In this paper, the rigid triaxiality in $^{154}$Sm is investigated using the newly proposed SU3-IBM theory. If the irreducible representation (irrep) of the ground state is (18,2) in the SU(3) symmetry limit, the new model can effectively reproduce the experimental data of $^{154}$Sm, showing good agreements with realistic energy spectra, B(E2) values, and quadrupole moments. This result further confirms the vality of the SU3-IBM for the description of the rigid triaxiality in realistic nuclei, and reveals the SU(3) dominance of the collectivity motions in nuclei.

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