Shape and energy spectra of Λ hypernuclei from a Skyrme-Hartree-Fock model and a beyond-mean-field calculation.

A triaxial shape-constrained Skyrme-Hartree-Fock mean-field model, employing a density-dependent pairing interaction and the NSC89 N Λ interaction, is used to investigate the potential energy surfaces of the Λ hypernuclei 13ΛC, 21ΛNe, 25,27ΛMg, and 27,29ΛSi. Angular momentum projection and particle number projection techniques are applied to the axially deformed mean-field states to restore the symmetries lost in the mean-field calculation, and the energy spectra and E2 transition probabilities of several (hyper)nuclei are studied, demonstrating the shrinkage effect of the Λ, which is analyzed in detail. [ABSTRACT FROM AUTHOR]