Is there a pion-Lambda-nucleon bound state?

TL;DR

This study investigates the possibility of a bound state in the pion-Lambda-nucleon system using both nonrelativistic and relativistic Faddeev equations, identifying conditions under which such a state could exist.

Contribution

The paper introduces a combined nonrelativistic and relativistic approach to search for bound states in the pion-Lambda-nucleon system, highlighting the role of specific meson-baryon resonances.

Findings

A bound state exists in the (I,JP)=(3/2,2+) channel under certain momentum conditions.

The bound state is driven by Delta(1232) and Sigma(1385) resonances.

Other similar strange and charmed systems are listed as potential candidates.

Abstract

We have searched for bound states in the pion-Lambda-nucleon system by solving the nonrelativistic Faddeev equations, as well as a relativistic version, with input separable pion-nucleon, pion-Lambda, and Lambda-nucleon interactions. A bound-state solution, driven by the Delta(1232) and Sigma(1385) p-wave meson-baryon resonances, was found in the channel (I,JP)=(3/2,2+), provided the Lambda lab momentum at which the Lambda-nucleon S=1,L=0,J=1 phase shift becomes negative is larger than about 750-800 MeV/c. Other strange and charmed pion-baryon-baryon systems that might have bound states of a similar nature are listed.