Strangeness -2 hypertriton

TL;DR

This study solves the Faddeev equations for the coupled $ ext{ΛΛN}$–$ ext{ΞNN}$ system to investigate the possible existence of a strangeness -2 hypertriton, finding it becomes bound when full coupling is considered.

Contribution

First-time solution of Faddeev equations for the coupled $ ext{ΛΛN}$–$ ext{ΞNN}$ system using a chiral quark model, revealing the bound state of a strangeness -2 hypertriton.

Findings

The $ ext{ΛΛN}$ system alone is unbound.

Coupling to $ ext{ΞNN}$ produces a bound state with about 0.5 MeV binding energy.

Results align with the non-existence of a stable $^3_Λ$H with isospin one.

Abstract

We have solved for the first time the Faddeev equations for the bound state problem of the coupled $\Lambda\Lambda N$--$\Xi NN$ system to study whether an hypertriton with strangeness -2 may exist or not. We make use of the interactions obtained from a chiral quark model describing the low-energy observables of the two-baryon systems with strangeness 0, -1, and -2 and three-baryon systems with strangeness 0 and -1. The $\Lambda\Lambda N$ system alone is unbound. However, when the full coupling to $\Xi NN$ is considered, the strangeness -2 three-baryon system with quantum numbers $(I,J^P)=(1/2,1/2^+)$ becomes bound, with a binding energy of about 0.5 MeV. This result is compatible with the non-existence of a stable $^3_\Lambda$H with isospin one.