Structure of Be Λ9 and Be Λ Λ10 using the beyond-mean-field Skyrme-Hartree-Fock approach

Based on the beyond-mean-field Skyrme-Hartree-Fock model, the up-to-date Skyrme-type NΛ interaction, SLL4, is used to investigate the properties of BeΛ9 comprehensively. Energies of different configurations, such as Be8- Λ[000]1/2+, Be8 - Λ[110]1/2-, Be8 - Λ[101]3/2-, and Be8 - Λ[101]1/2- are given and used to study the effects of Λ occupying different orbitals. The calculated energy spectra, including both positive- and negative-parity levels, are given and compared to the experimental data. The observed positive-parity spin doublets (3/2+,5/2+) are successfully reproduced, but the energy difference needs further investigation. The two well-known band structures corresponding to the genuine hypernuclear states and the Be9-analog states are also obtained and compared with the observed ones. The shrinkage effect of Λ occupying Λ[000]1/2+ is investigated through the density distributions of nuclear core. And finally, the E2 transition rates are given and compared with the observed data and with the results of the hypernuclear particle-rotor model. Properties of BeΛΛ10 are also studied to show the completeness of this current model.