The relativistic chiral Lagrangian for decuplet and octet baryons at next-to-leading order

TL;DR

This paper constructs a complete relativistic chiral Lagrangian at next-to-leading order for baryon octet and decuplet states, detailing the terms, their physical implications, and providing predictions for radiative decays.

Contribution

It introduces a minimal, complete relativistic Lagrangian at next-to-leading order for SU(3) chiral perturbation theory involving baryon octet and decuplet states, with explicit term enumeration and physical constants.

Findings

13 terms for decuplet sector

6 terms for octet-decuplet transition

Predictions for radiative decays

Abstract

A complete and minimal relativistic Lagrangian is constructed at next-to-leading order for SU(3) chiral perturbation theory in the presence of baryon octet and baryon decuplet states. The Lagrangian has 13 terms for the pure decuplet sector, 6 terms for the transition sector from baryon octet to decuplet and (as already known from the literature) 16 terms for the pure octet sector. The minimal field content of 25 of these terms is meson-baryon four-point interactions. 3 terms give rise to the mass splitting for baryon octet and decuplet states, respectively. 2 terms give rise to overall mass shifts. 4 terms provide anomalous magnetic moments and a decuplet-to-octet magnetic transition moment. 1 term leads to an axial vector transition moment. It is shown that meson-baryon three-point coupling constants come in at leading order whereas no additional one appears in the minimal Lagrangian at next-to-leading order. Those low-energy constants that give rise to mass splitting and magnetic moments, respectively, are determined. Predictions are provided for radiative decays of decuplet to octet baryons.