中文摘要：

除了几个幻数核呈球形外,原子核大都是变形的,例如椭球形。现代核物理实验已发现,原子核可以呈＂梨形＂形变,即具有反射不对称性。理论研究预言,原子核还可能具有＂金字塔＂形变,即四面体对称性,而实验上还未找到原子核的这种新对称性。文章从强相互作用量子多体体系的对称性及其破缺的基本规律出发,阐明原子核四面体形变的形成机制,并介绍其理论描述。同时讨论寻找四面体形变原子核的基本方法和最新实验研究进展。

英文摘要：

Atomic nuclei are usually deformed except for a few magic nuclei which are spherical in shape. Modern nuclear experiments have discovered that some nuclei may have a pear-like shape, with reflection asymmetry. According to theory, other nuclei may also have a pyr- amid-like shape with tetrahedral symmetry, but this new nuclear symmetry has not yet been discovered experimentally. This paper aims to explain the formation mechanism of the tetrahedral symmetry as well as give a theoretical description based on the symmetry and symmetry-breaking of a quantum strong interaction many-body system. The basic ways to search for tetrahedral nuclei and recent experimental developments are also discussed.