Auxiliary Field Diffusion Monte Carlo study of the hyperon-nucleon interaction in Λ-hypernuclei

We investigate the role of two- and three-body Λ-nucleon forces by computing the ground state of a few Λ-hypernuclei with the Auxiliary Field Diffusion Monte Carlo algorithm. Calculations have been performed for masses up to A=41, including some open-shell hypernuclei. The results show that the use of a bare hyperon-nucleon force fitted on the available scattering data yields a consistent overestimate of the Λ-separation energy BΛ. The inclusion of a hyperon-nucleon-nucleon interaction systematically reduces BΛ, leading to a qualitatively good agreement with experimental data over the range of masses investigated.