Meson Decay Constant Predictions of the Valence Approximation to Lattice QCD

We evaluate $f_{\pi}/ m_{\rho}$, $f_K/ m_{\rho}$, $1/f_{\rho}$, and $m_{\phi}/(f_{\phi} m_{\rho})$, extrapolated to physical quark mass, zero lattice spacing and infinite volume, for lattice QCD with Wilson quarks in the valence (quenched) approximation. The predicted $m_{\phi}/(f_{\phi} m_{\rho})$ differs from experiment by less than its statistical uncertainty of approximately 15\%. The other three constants are 10\% to 20\% below experiment, equivalent to between one and two times the corresponding statistical uncertainties.