Faddeev-Yakubovsky calculations for A=4 hypernuclear systems

We present results for the Λ separation energies of the four-body hypernuclei 4ΛHe and 4ΛH based on solutions of the Yakubovsky equations for these systems. Our results show that none of the Nijmegen soft-core models or the Jülich A˜ model correctly binds all four-body hypernuclei states simultaneously. We discuss the possibilities to constrain hyperon-nucleon interactions using the charge-dependence of the four-body Λ separation energies.