Coupled channel Faddeev calculations of a (Kbar-N-pi) quasibound state

TL;DR

This paper uses coupled channel Faddeev calculations with realistic interactions to predict a new quasibound state in the (Kbar-N-pi) system, indicating a molecular Sigma(1570) resonance near threshold.

Contribution

It introduces a detailed three-body calculation with relativistic kinematics to predict a novel quasibound state in the (Kbar-N-pi) system, expanding understanding of hyperon resonances.

Findings

Predicted a (Kbar-N-pi) quasibound state at ~1570 MeV

Identified a Sigma(1570) resonance with molecular structure

Estimated the state’s width to be greater than 60 MeV

Abstract

The (Kbar-N-pi) system is studied using separable interactions fitted to data available on the s-wave (Kbar-N)--(pi-Y) subsystem and the p-wave (pi-N),(pi-Y),(pi-pi) and (pi-Kbar) subsystems. Three-body (Kbar-N-pi)--(pi-Y-pi) coupled channel Faddeev equations with relativistic kinematics are solved in search for quasibound poles in the complex plane, leading to a I(JP)=1(3/2-) (Kbar-N-pi) quasibound state at M ~ (1570 +/- 10) MeV and width greater than 60 MeV near the (Kbar-N-pi) threshold. A D13 Sigma(1570) resonance of molecular structure is thus predicted.