Electromagnetic contribution to $\Sigma$-$\Lambda$ mixing using lattice QCD+QED

TL;DR

This paper introduces a new lattice QCD+QED method to quantify the electromagnetic contribution to $ ext{Σ}^0$-$ ext{Λ}^0$ mixing, enhancing understanding of isospin and flavor symmetry breaking.

Contribution

The authors develop a novel scheme for calculating $ ext{Σ}^0$-$ ext{Λ}^0$ mixing that incorporates electromagnetic effects and allows comparison with QCD-only scenarios.

Findings

Scheme successfully compares QCD-only and QCD+QED mixing.

Results align well with previous determinations.

Provides insights into isospin and flavor symmetry breaking mechanisms.

Abstract

Mixing in the $\Sigma^0$-$\Lambda^0$ system is a direct consequence of broken isospin symmetry and is a measure of both isospin-symmetry breaking as well as general SU(3)-flavour symmetry breaking. In this work we present a new scheme for calculating the extent of $\Sigma^0$-$\Lambda^0$ mixing using simulations in lattice QCD+QED and perform several extrapolations that compare well with various past determinations. Our scheme allows us to easily contrast the QCD-only mixing case with the full QCD+QED mixing.