The effects of flavour symmetry breaking on hadron matrix elements

TL;DR

This paper studies how breaking SU(3) flavour symmetry affects octet baryon matrix elements, providing constraints useful for lattice QCD extrapolations and analyzing these effects through numerical lattice calculations.

Contribution

It introduces a flavour expansion framework around the SU(3) symmetric point and demonstrates its utility in constraining baryon matrix elements during symmetry breaking.

Findings

Highly constrained expansions along specific mass trajectories.

Numerical lattice calculations of vector and axial matrix elements.

Enhanced understanding of flavour symmetry breaking effects.

Abstract

By considering a flavour expansion about the SU(3)-flavour symmetric point, we investigate how flavour-blindness constrains octet baryon matrix elements after SU(3) is broken by the mass difference between the strange and light quarks. We find the expansions to be highly constrained along a mass trajectory where the singlet quark mass is held constant, which proves beneficial for extrapolations of 2+1 flavour lattice data to the physical point. We investigate these effects numerically via a lattice calculation of the flavour-conserving and flavour-changing matrix elements of the vector and axial operators between octet baryon states.