Scalar Λ N and Λ Λ interaction in a chiral unitary approach

We study the central part of the {lambda}N and {lambda}{lambda} potential by considering the correlated and uncorrelated two-meson exchange in addition to the {omega} exchange contribution. The correlated two-meson exchange is evaluated within a chiral unitary approach. We find that a short-range repulsion is generated by the correlated two-meson potential, which also produces an attraction in the intermediate-distance region. The uncorrelated two-meson exchange produces a sizable attraction in all cases that is counterbalanced by the {omega} exchange contribution.