Flavor singlet meson mass in the continuum limit in two-flavor lattice QCD

Abstract

We present results for the mass of the [Formula Presented] meson in the continuum limit for two-flavor lattice QCD, calculated on the CP-PACS computer, using a renormalization-group-improved gauge action, and the Sheikoleslami-Wohlert fermion action with a tadpole-improved [Formula Presented] The correlation functions are measured at three values of the coupling β corresponding to the lattice spacing [Formula Presented] 0.16, 0.11 fm and for four values of the quark mass parameter κ corresponding to [Formula Presented] 0.75, 0.7, 0.6. For each (β, κ) pair, 400–800 gauge configurations are used. The two-loop diagrams are evaluated using a noisy source method. We calculate [Formula Presented] propagators using both smeared and local sources, and find that excited state contaminations are much reduced by smearing. A full analysis for the smeared propagators gives [Formula Presented] in the continuum limit, where the second error represents the systematic uncertainty coming from varying the functional form for chiral and continuum extrapolations. © 2003 The American Physical Society.