Particle-particle random-phase approximation applied to beryllium isotopes

This paper is dedicated to the study of even-even ^8-14Be isotopes, which uses the particle-particle random-phase approximation that accounts for two-body correlations in the core nucleus. A better description of energies and two-particle amplitudes is obtained in comparison with models that assume a neutron closed-shell (or subshell) core. A Woods-Saxon potential corrected by a phenomenological particle-vibration coupling term has been used for the neutron-core interaction and the D1S Gogny force for the neutron-neutron interaction. Calculated ground-state properties as well as excited-state ones are discussed and are compared to experimental data. In particular, results suggest the same 2s1/2-1p1/2 shell inversion in ¹³Be as in ¹¹Be.