State mixing and masses of the π0, η and η′ mesons from nf=1+1+1 lattice QCD+QED

We present a lattice analysis of the light pseudoscalar mesons with consideration for the mixing between the flavor-neutral states π0, η and η′. We extract the masses and flavor compositions of the pseudoscalar meson nonet in nf=1+1+1 lattice QCD+QED around an SU(3)-flavor symmetric point, and observe flavor-symmetry features of the extracted data, along with preliminary extrapolation results for the flavor compositions at the physical point. A key result of this work is the observed mass splitting between the π0 and η on our ensembles, which is found to exhibit behavior that is simply related to the corresponding flavor compositions.