$\Xi^- t$ quasibound state instead of $\Lambda\Lambda nn$ bound state

TL;DR

This study investigates whether the $ m \Lambda\Lambda nn$ system can form a bound state, concluding it cannot, but identifies a $ m \Xi^- $ quasibound state above the threshold using coupled-channel models.

Contribution

The paper introduces a combined three-body and four-body approach to analyze coupled hypernuclear systems, revealing a $ m \Xi^- $ quasibound state instead of a $ m \Lambda\Lambda nn$ bound state.

Findings

$ m \Lambda\Lambda nn$ bound state is excluded.

A $ m \Xi^- $ quasibound state is found.

Coupled-channel effects are significant in hypernuclear binding analysis.

Abstract

We study the coupled $\Lambda\Lambda nn-\Xi^- pnn$ system to check whether the inclusion of channel coupling is able to bind the $\Lambda\Lambda nn$ system. We use a separable potential three-body model of the coupled $\Lambda\Lambda nn - \Xi^- pnn$ system as well as a variational four-body calculation with realistic interactions. Our results exclude the possibility of a $\Lambda\Lambda nn$ bound state by a large margin. However, we have found a $\Xi^- t$ quasibound state above the $\Lambda\Lambda nn$ threshold.