Setting the Scale Using Baryon Masses with Isospin-Breaking Corrections

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 $a\approx0.076\,\text{fm}$.