Relativistic SU(3) chiral baryon-baryon Lagrangian up to order q^2

TL;DR

This paper develops a comprehensive relativistic chiral Lagrangian for baryon-baryon interactions in SU(3) flavor symmetry up to order q^2, including contact terms and their implications for scattering potentials.

Contribution

It constructs the most general covariant chiral Lagrangian for baryon-baryon contact interactions in SU(3) up to order q^2, incorporating symmetry constraints and eliminating redundant terms.

Findings

Derived contact potentials for baryon-baryon scattering in low partial waves.

Provided a systematic framework for including mesons and photons in baryon interactions.

Ensured invariance under key symmetries and used algebraic identities to simplify the Lagrangian.

Abstract

We construct the most general chiral effective Lagrangian for baryon-baryon contact interactions in flavor SU(3) up to order q^2 using a covariant power counting. A subset of these contact terms contributes to the baryon-baryon potential in chiral effective field theory. The Lorentz invariant effective Lagrangian is constructed to fulfill the invariance under charge conjugation, parity transformation, Hermitian conjugation and the local chiral symmetry group SU(3)_L x SU(3)_R. Goldstone bosons and external fields are included as well, thus providing additional four-baryon contact vertices involving e.g. pseudoscalar mesons and/or photons. In order to eliminate the linearly dependent terms, we use the Fierz identities, the equations of motion, and a Cayley-Hamilton relation for SU(3). As an application the baryon-baryon scattering contact potentials in low partial waves are considered.