Nonexistence of a $\Lambda nn$ bound state

TL;DR

This paper demonstrates through detailed calculations that a bound state of two neutrons and a Lambda hyperon ($^3_ extLambda n$) does not exist, challenging recent claims of such a state.

Contribution

The study provides a comprehensive Faddeev calculation using realistic baryon-baryon interactions to disprove the existence of the $ extLambda nn$ bound state.

Findings

No bound state found for $ extLambda nn$ system.

Realistic interactions from the constituent quark cluster model do not support such a state.

Results align with known two-body hyperon-nucleon data.

Abstract

It has been recently suggested the existence of a neutral bound state of two neutrons and a $\Lambda$ hyperon, $^3_\Lambda n$. We point out that using either simple separable potentials or a full-fledged calculation with realistic baryon-baryon interactions derived from the constituent quark cluster model there is no possibility for the existence of such a $\Lambda nn$ bound state. For this purpose, we performed a full Faddeev calculation of the $\Lambda nn$ system in the $(I,J^P)=(1,1/2^+)$ channel using the interactions derived from the constituent quark cluster model which describe well the two-body $NN$ and $NY$ data and the $\Lambda np$ hypertriton.