Microscopic three-cluster study of the low-energy 9 Be photodisintegration

Abstract

The 9Be and 9B nuclei are investigated in a microscopic three-cluster model involving α + α + n (or α + α + p) configurations. The 8Be (0 + , 2 + ) + n and 5He (3/2 - , 1/2 - ) + α (or mirror) channels are included by taking account of the unstable nature of 8Be and 5He. Spectroscopic properties of 9Be and 9B are analyzed. We show that the 5He + α configurations cannot be neglected to derive accurate results. The 9Be(γ,αα)n photodisintegration cross-section is shown to be mainly determined by 8Be + n channels at low energies, but 5He + α channels become important beyond E γ≈ 4 MeV.