On non-mesonic decay of light Λ-hypernuclei

Abstract

The Dalitz phenomenological approach to non-mesonic decay of s-shell hypernuclei is extended to 1 p-shell hypernuclei using the closure approximation over residual nucleus states. The developed formalism applied to the analysis of the BNL data on decays of Λ 12 C, Λ 11 B, Λ 9 Be and Λ 5 He. The observed proximity of the ratios γ = Γ n Γ p for Λ 12 C and Λ 11 B is accounted for by a similarity of structure factors. Constraints on the permissible values of γ( Λ 12 C) and γ( Λ 11 B) have been found. The equality of the γ′s for 1 p-shell hypernuclei with the nuclear-core spin and isospin J N = T = 0 has been established. Proportionality of Γ nm , Γ n and Γ p to the number of nucleons in these hypernuclei has been shown. A qualitative explanation of the observed ratios Γ nm( Λ 12C) Γ nm( Λ 5He) and Γ nm( Λ 9Be) Γ nm( Λ 5He) is given.