Breakdown of shell closure in helium-10

• Main Authors: Gurgen M. Ter-Akopian, Sergey I. Sidorchuk, Leonid V. Grigorenko
• Format: Reference Entry
• Language: English
• DOI: 10.1036/1097-8542.YB130190

The study of exotic nuclei at the edges of nuclear stability is one of the most important developments in modern nuclear physics. Unusual forms of nuclear dynamics often arise here. One of the most prominent phenomena encountered is shell breakdown—the deviation from the expected shell structure in these exotic nuclei. On the one hand, in the nuclear shell model, helium-10 (10He) is a “double-magic” nucleus with Z = 2 and N = 8. On the other hand, it has an enormous neutron excess; its neutron number (N) to proton number (Z) ratio equals 4, which brings it to the edge of nuclear matter asymmetry. Thus, the 10He nucleus is an important system for the development of our understanding of nuclei located far from the beta stability valley and even beyond the neutron and proton drip lines. Here we present new insights into the basic properties of this nucleus, illuminating its shell structure and indicating its strong deviation from the simple shell population picture.