Few-Body Aspects of Hypernuclear Physics

Abstract

On the basis of the three- and four-body structure calculations of Λ 4 H and Λ 4 He, Λ 7 Λ He, Λ 7 Λ Li, Λ 8 ΛLi, Λ 9 Λ Li, Λ 9 Λ Be and Λ 10 Λ Be, it is emphasized that there are many interesting and important few-body problems in hypernuclear physics. By performing four-body calculation with both 3N + Λ and 3N + Σ channels with realistic NN and YN interactions, we show that the Σ-channel component plays an important role in making Λ 4 H and Λ 4 He. Energy levels of the double-Λ hypernuclei Λ 7 Λ He, Λ 7 Λ Li, Λ 8 ΛLi, Λ 9 Λ Li, Λ 9 Λ Be and Λ 10 Λ Be are predicted on the basis of the α + x + Λ + Λ four-body model with x = n, p, d, t,3He and a, respectively The Demachi-Yanagi event, observed recently for Λ 10 Λ Be, is interpreted as discovery, of its 2+ excited state by the present calculation.