# Parity partners in the baryon resonance spectrum

## TL;DR

This paper models the spectrum of baryons and their parity partners using a symmetry-preserving contact interaction, revealing the internal diquark correlations and the role of orbital angular momentum in their structure.

## Contribution

It introduces a novel calculation framework for baryon spectra incorporating parity partners and diquark correlations within a contact interaction model.

## Key findings

- Reasonable mass predictions for baryons and parity partners.
- Ground-state baryons mainly composed of like-parity diquarks.
- Odd-parity baryons have significant orbital angular momentum contributions.

## Abstract

We describe a calculation of the spectrum of flavour-SU(3) octet and decuplet baryons, their parity partners, and the radial excitations of these systems, made using a symmetry-preserving treatment of a vector-vector contact interaction as the foundation for the relevant few-body equations. Dynamical chiral symmetry breaking generates nonpointlike diquarks within these baryons and hence, using the contact interaction, flavour-antitriplet scalar, pseudoscalar and vector, and flavour-sextet axial-vector quark-quark correlations can all play an active role. The model yields reasonable masses for all systems studied, and Faddeev amplitudes for ground states and associated parity partners that sketch a realistic picture of their internal structure: ground-state, even parity baryons are constituted, almost exclusively, from like-parity diquark correlations; but orbital angular momentum plays an important role in the rest-frame wave functions of odd-parity baryons, whose Faddeev amplitudes are dominated by odd-parity diquarks.