Stable bound states of $N$'s, $Λ$'s, and $Ξ$'s

Abstract

We review our recent work about the stability of strange few-body systems containing N 's, Λ's, and Ξ's. We make use of local central Yukawa-type Malfliet-Tjon interactions reproducing the lowenergy parameters and phase shifts of the nucleon-nucleon system and the latest updates of the hyperon-nucleon and hyperon-hyperon ESC08c Nijmegen potentials. We solve the three-and fourbody bound-state problems by means of Faddeev equations and a generalized Gaussian variational method, respectively. The hypertriton, Λnp (I)J P = (1/2)1/2 + , is bound by 144 keV; the recently discussed Λnn (I)J P = (1/2)1/2 + system is unbound, as well as the ΛΛnn (I)J P = (1)0 + system, being just above threshold. Our results indicate that the ΞN N , ΞΞN and ΞΞN N systems with maximal isospin might be bound.