Three-body structure of the $nn\Lambda$ system with $\Lambda N-\Sigma N$ coupling

TL;DR

This paper investigates the three-body $nn\Lambda$ system considering $\Lambda N-\Sigma N$ coupling, using interactions that reproduce known hypernuclei, and finds no bound state contrary to some experimental interpretations.

Contribution

It provides a detailed theoretical analysis of the $nn\Lambda$ system with explicit $\Lambda N-\Sigma N$ coupling, challenging previous experimental claims.

Findings

No $^3_{\Lambda}n$ bound state found.

Interactions reproduce known hypernuclei binding energies.

Contradicts HypHI collaboration's interpretation.

Abstract

The structure of the three-body $nn\Lambda$ system, which has been observed recently by the HypHI collaboration, is investigated taking $\Lambda N-\Sigma N$ coupling explicitly into account. The $YN$ and $NN$ interactions employed in this work reproduce the binding energies of $^3_{\Lambda}$H, $^4_{\Lambda}$H and $^4_{\Lambda}$He. We do not find any $^3_{\Lambda}n$ bound state, which contradicts the interpretation of the data reported by the HypHI collaboration.