Robustness of chiral symmetry in atomic nuclei with reflection-asymmetric shapes

• 作 者: Costel Marian Petrache
• 机 构: IJCLab, CNRS/IN2P3, Univ Paris-Saclay, F-91405 Orsay, France
• 出 处: 科学通报（英文版）
• 发表日期: 2020年23期

Nearly degenerate quantum states arise from fundamental symmetries, which are often broken in finite many-body systems like atomic nuclei.Chirality can be static, like in molecules composed of more than four atoms, or dynamic, like in particle physics distinguishing between parallel and antiparallel orientation of the spin with respect to the momentum of massless fermions.Frauendoff and Meng [1] pointed out that the rotation of an axial-asymmetric (triaxial) nucleus can attain a chiral character: the angular momentum vector (J) introduces chirality by selecting different left-handed or right-handed systems in the intrinsic frame of reference of a triaxial nucleus, giving rise to degenerate rotational bands because all octants are energetically equivalent.The nuclear chirality is therefore dynamic, resulting from the combination of dynamics induced by the angular momentum, and geometry induced by the triaxial shape.More than 60 chiral doublet bands have been reported in A ～ 80, 100, 130, and 190 mass regions [2], which are regarded as fingerprints of triaxial deformation.