Light Ξ hypernuclei

Arguments in favor of a light ΞNN hypernucleus with (I)JP=(3/2)1/2+ are presented, within the uncertainties of our knowledge of the baryon-baryon strangeness -2 interactions. If bound, this ΞNN state, being decoupled from the lowest NΛΛ system, would be stable. It will also benefit from additional binding due to the electromagnetic interaction what makes it worthwhile to look for. We show how the equivalent state with J=3/2 could never be bound in spite of the attractive interaction of the two-body subsystems. We illustrate our discussion with a full-fledged Faddeev calculation of the ΞNN system using simple potentials that mimic more elaborate interactions. We also make contact with different recent phenomenological interactions from the literature, like the ESC08 Nijmegen potential or quark-model based potentials.