Microscopic study of α clustering in the 9,10,11Be isotopes Original Research Article

The 9,10,11Be nuclei are described in a microscopic multicluster model involving α+α+n, α+α+n+n and α+α+n+n+n configurations, respectively. The effect of α clustering is shown to decrease from 9Be to 11Be. In 9Be, we find 1/2+, 1/2− and 3/2− bands which are well supported by experimental data. For 10Be, in addition to the ground-state band, we predict 1+ and 1− rotational bands; α+6He cluster states are also discussed. A 1/2+ band is obtained in 11Be, but negative-parity states do not present significant clustering. The existence of a 3/2− band, suggested recently, is therefore not supported by the model.