Odd Parity Light Baryon Resonances

TL;DR

This paper employs an SU(6) extended chiral Lagrangian within a coupled channel approach to identify and interpret baryon resonances, predicting properties of several Xi and Omega states not yet experimentally determined.

Contribution

It introduces a unified SU(6) framework to analyze meson-baryon scattering and predict the spin-parity of several unknown odd parity baryon resonances.

Findings

Many poles correspond to known N, Delta, Sigma, Lambda, Xi resonances.

Predictions for the spin-parity of Xi(1620), Xi(1690), Xi(1950), Xi(2250), Omega(2250), Omega(2380).

Most low-lying odd parity baryon resonances relate to SU(6) multiplets.

Abstract

We use a consistent SU(6) extension of the meson-baryon chiral Lagrangian within a coupled channel unitary approach in order to calculate the T-matrix for meson-baryon scattering in s-wave. The building blocks of the scheme are the pion and nucleon octets, the rho nonet and the Delta decuplet. We identify poles in this unitary T-matrix and interpret them as resonances. We study here the non exotic sectors with strangeness S=0,-1,-2,-3 and spin J=1/2, 3/2 and 5/2. Many of the poles generated can be associated with known N, Delta, Sigma, Lambda and Xi resonances with negative parity. We show that most of the low-lying three and four star odd parity baryon resonances with spin 1/2 and 3/2 can be related to multiplets of the spin-flavor symmetry group SU(6). This study allows us to predict the spin-parity of the Xi(1620), Xi(1690), Xi(1950), Xi(2250), Omega(2250) and Omega(2380) resonances, which have not been determined experimentally yet.