A-dependence of ⋀ ⋀ bond energies in double-⋀ hypernuclei

The A-dependence of the bond energy ΔB⋀ ⋀ of the ⋀ ⋀ hypernuclear ground states is calculated in a three-body ⋀+⋀+^AZ model and in the Skyrme-Hartree-Fock approach. Various ⋀ ⋀ and ⋀-nucleus or ⋀N potentials are used and the sensitivity of ΔB⋀ ⋀ to the interactions is discussed. It is shown that in medium and heavy ⋀ ⋀ hypernuclei, ΔB⋀ ⋀ is a linear function of r_⋀ ^-3, where r_⋀ is rms radius of the hyperon orbital. It looks unlikely that it will be possible to extract ⋀ ⋀ interaction from the double-⋀ hypernuclear energies only, the additional information about the ⋀-core interaction, in particular, on r_⋀ is needed.