Lattice Determination of Heavy-Light Decay Constants

This is the authors' abstract. We don't add key points for this paper.

We report on the MILC Collaboration's calculation of fB, f_Bₛ, fD, f_Dₛ, and their ratios. Our central values come from the quenched approximation, but the quenching error is estimated from NF0ex0ex=0ex0ex2 dynamical staggered lattices. We use Wilson light valence quarks and Wilson and static heavy quarks. We find, for example, fB0ex0ex=0ex0ex157±11_-9-0⁺²⁵⁺²³0ex0exMeV, f_Bₛ/fB0ex0ex=0ex0ex1.11±0.02_-0.03+0.04±0.03, f_Dₛ0ex0ex=0ex0ex210±9_-9-1⁺²⁵⁺¹⁷0ex0exMeV, and fB/f_Dₛ0ex0ex=0ex0ex0.75±0.03_-0.02-0.00+0.04+0.08, where the errors are statistical, systematic (within the quenched approximation), and systematic (of quenching), respectively.