What does the free space ΛΛ interaction predict for ΛΛ hypernuclei?

Data on ΛΛ hypernuclei provide a unique method to learn details about the strangeness S=-2 sector of the baryon-baryon interaction. From the free space Bonn-Juelich potentials, determined from data on baryon-baryon scattering in the S=0, -1 channels, we construct an interaction in the S=-2 sector to describe the experimentally known ΛΛ hypernuclei. After including short-range (Jastrow) and RPA correlations, we find masses for these ΛΛ hypernuclei in a reasonable agreement with data, taking into account theoretical and experimental uncertainties. Thus, we provide a natural extension, at low energies, of the Bonn-Juelich one-boson exchange potentials to the S=-2 channel