[Formula Presented] mixing in quenched lattice QCD

Abstract

We present our results of lattice calculations of B parameters, which parametrize (Formula presented) transition amplitudes together with the leptonic decay constant. Calculations are made in the quenched approximation at (Formula presented) 5.9, 6.0 and 6.1, using NRQCD action for heavy quarks and the (Formula presented)-improved Wilson action for light quarks. The operators are perturbatively renormalized including the correction of (Formula presented) We examine the scaling behavior of B parameters, and discuss the systematic uncertainties based on the results with several different truncations of higher order terms in (Formula presented) and (Formula presented) expansions. We find (Formula presented) (Formula presented) and (Formula presented) in the quenched approximation. The errors represent statistical and systematic errors as well as the uncertainty in the determination of strange quark mass. © 2003 The American Physical Society.