Three-flavor chiral effective model with four baryonic multiplets within the mirror assignment

TL;DR

This paper develops a three-flavor chiral effective model incorporating four baryonic multiplets with mirror assignment, fitting experimental data, and analyzing chiral partner relationships among nucleonic states.

Contribution

It introduces a novel three-flavor model with four baryonic multiplets under mirror assignment, extending previous two-flavor approaches and identifying chiral partners among nucleon resonances.

Findings

Identifies chiral partner pairs among nucleon states.

Fits model parameters to experimental masses and decay data.

Shows mass evolution under chiral symmetry restoration.

Abstract

We study three-flavor octet baryons by using the so-called extended Linear Sigma Model (eLSM). Within a quark-diquark picture, the requirement of a mirror assignment naturally leads to the consideration of four spin-$\frac{1}{2}$ baryon multiplets. A reduction of the Lagrangian to the two-flavor case leaves four doublets of nucleonic states which mix to form the experimentally observed states $N(939)$, $N(1440)$, $N(1535)$ and $N(1650)$. We determine the parameters of the nucleonic part of the Lagrangian from a fit to masses and decay properties of the aforementioned states. By tracing their masses when chiral symmetry is restored, we conclude that the pairs $N(939)$, $N(1535)$ and $N(1440)$, $N(1650)$ form chiral partners.