Non-degenerate light quark masses from 2+1f lattice QCD+QED

TL;DR

This paper calculates the effects of isospin breaking on light quark masses using lattice QCD+QED with chiral perturbation theory, providing more precise non-degenerate quark mass estimates.

Contribution

It introduces a new calculation of non-degenerate light quark masses incorporating electromagnetic corrections on 2+1 flavor lattice QCD+QED ensembles.

Findings

Determined non-degenerate light quark masses with electromagnetic effects.

Used chiral perturbation theory to renormalize quark masses.

Improved precision over previous lattice QCD+QED studies.

Abstract

We report on a calculation of the effects of isospin breaking in Lattice QCD+QED. This involves using Chiral Perturbation Theory with Electromagnetic corrections to find the renormalized, non-degenerate, light quark masses. The calculations are carried out on QCD ensembles generated by the RBC and UKQCD collaborations using Domain Wall Fermions and the Iwasaki and Iwasaki+DSDR Gauge Actions with unitary pion masses down to 170 MeV. Non-compact QED is treated in the quenched approximation. The simulations use a $32^3$ lattice size with $a^{-1}=2.28(3)$ GeV (Iwasaki) and 1.37(1) (Iwasaki+DSDR). This builds on previous work from the RBC/UKQCD collaboration with lattice spacing $a^{-1}=1.78(4)$ GeV.