Neutral B Meson Mixing and Heavy-light Decay Constants from Quenched Lattice QCD

We present high-statistics results for neutral $B$-meson mixing and heavy-light-meson leptonic decays in the quenched approximation from tadpole-improved clover actions at $\beta = 6.0$ and $\beta = 6.2$. We consider quantities such as $B_{B_{d(s)}}$, $f_{D_{d(s)}}$, $f_{B_{d(s)}}$ and the full $\Delta B=2$ matrix elements as well as the corresponding SU(3)-breaking ratios. These quantities are important for determining the CKM matrix element $|V_{td}|$.