Single-particle and collective motions from nuclear many-body correlation (PCM2025)

Non-Axial Octupole Deformation in Atomic Nuclei: A Group-Theoretical Comparison of Tetrahedral and Octahedral Symmetries

5 Mar 2025, 15:34

1m

Main Lecture Hall (University of Aizu)

Poster session

Speaker

Xiaosheng Xing (RCNP)

Description

Recent experimental advancements have provided substantial evidence for octupole deformation in atomic nuclei, revealing complex deformation modes beyond the quadrupole level. Conventional axially symmetric models struggle to fully capture these deformations, necessitating an exploration of non-axial modes. Previous studies employing the Oh group symmetry faced limitations, as spatial inversion symmetry inherently excludes rotational degrees of freedom in the decomposition of $l$ = 3 spherical harmonics. To overcome this, we investigate the $T_d$ (tetrahedral) and $O$ (octahedral) groups, both of which successfully yield the $T_1$ irreducible representation—associated with rotational degrees of freedom—allowing for the construction of an intrinsic coordinate system for octupole deformation. However, differences in the decomposition of one-dimensional irreducible representations under $T_d$ and $O$ symmetries lead to distinct linear combinations of spherical harmonics as basis functions. This raises fundamental questions regarding the optimal choice of symmetry for parameterizing octupole deformation in nuclei. By systematically exploring these symmetry constraints, this work aims to establish a robust group-theoretical framework for describing non-axial octupole modes, paving the way for refined theoretical models of nuclear structure.

Presentation materials

poster - Xiaosheng Xing.pdf