Setting the Scale Using Baryon Masses with Isospin-Breaking Corrections

TL;DR

This paper discusses incorporating isospin-breaking effects from quark mass differences and electromagnetic interactions into lattice QCD calculations of baryon masses to improve precision in setting the lattice scale.

Contribution

It introduces a perturbative method to include isospin-breaking corrections in baryon mass calculations on $N_f=2+1$ ensembles, advancing precision in lattice QCD.

Findings

Results obtained at two pion masses, 290 MeV and 215 MeV.

Leading order isospin-breaking corrections applied.

Progress towards precise lattice scale determination.

Abstract

We present the status of an ongoing project aimed at the inclusion of isospin-breaking corrections arising from the non-degeneracy of the light quark masses and electromagnetic interactions in calculations of the low-lying octet and decuplet baryon masses. Our ultimate goal is to perform a precision determination of the lattice scale including isospin-breaking effects. We apply the perturbative formalism to isospin-symmetric $N_f=2+1$ CLS ensembles. We show results on baryon masses up to leading order in isospin-breaking corrections on two ensembles with $m_\pi\approx290\,\text{MeV}$ and $m_\pi\approx215\,\text{MeV}$ at a lattice spacing of $a\approx0.076\,\text{fm}$.