Isospin-breaking Effects in Octet and Decuplet Baryon Masses

TL;DR

This paper calculates the effects of isospin-breaking on octet and decuplet baryon masses using lattice QCD with perturbative corrections for non-degenerate quark masses and electromagnetic interactions.

Contribution

It introduces a perturbative approach to include isospin-breaking effects in baryon mass calculations on $N_f=2+1$ CLS ensembles, utilizing a group-theoretical operator construction.

Findings

Quantifies isospin-breaking effects on baryon masses.

Develops a group-theoretical classification for baryon interpolators.

Provides a framework for including electromagnetic effects in lattice QCD.

Abstract

We present work designed to compute baryon masses on $N_f = 2 + 1$ CLS ensembles including isospin-breaking effects due to non-degenerate light quark masses and electromagnetic interactions. These effects are determined at leading order via a perturbative expansion around the iso-symmetric theory. We furthermore apply a group-theoretical operator construction for the various interpolators describing the different members of the baryon octet and decuplet based on a classification by spin, parity, and flavor content.