Estimating the unquenched strange quark mass from the lattice axial Ward identity

Abstract

We present a determination of the strange quark mass for two flavors (${n}_{f}=2$) of light dynamical quarks using the axial Ward identity. The calculations are performed on the lattice using $O(a)$ improved Wilson fermions and include a fully nonperturbative determination of the renormalization constant. In the continuum limit we find ${m}_{s}^{\overline{\mathrm{MS}}}(2\text{ }\text{ }\mathrm{GeV})=111(6)(4)(6)\text{ }\text{ }\mathrm{MeV}$, using the force scale ${r}_{0}=0.467\text{ }\text{ }\mathrm{fm}$, where the first error is statistical, the second and third are systematic due to the fit and scale uncertainties, respectively. Results are also presented for the light quark mass and the chiral condensate. The corresponding results are also given for ${r}_{0}=0.5\text{ }\text{ }\mathrm{fm}$.