Decay constants of charm and beauty pseudoscalar heavy-light mesons on fine lattices

TL;DR

This paper calculates decay constants of charm and beauty heavy-light mesons using quenched lattice QCD on fine lattices, providing precise values with detailed error analysis.

Contribution

The study presents the first high-precision quenched lattice QCD calculations of heavy-light meson decay constants at a fine lattice spacing of 0.04 fm.

Findings

Decay constants for D_s, D, B_s, and B mesons with statistical and systematic errors.

Results for f_K, f_π, and the ρ meson mass included.

Use of non-perturbatively improved Wilson fermions and currents.

Abstract

We compute decay constants of heavy-light mesons in quenched lattice QCD with a lattice spacing of a ~ 0.04 fm using non-perturbatively O(a) improved Wilson fermions and O(a) improved currents. We obtain f_{D_s} = 220(6)(5)(11) MeV, f_D = 206(6)(3)(22) MeV, f_{B_s} = 205(7)(26)(17) MeV and f_B = 190(8)(23)(25) MeV, using the Sommer parameter r_0 = 0.5 fm to set the scale. The first error is statistical, the second systematic and the third from assuming a +-10% uncertainty in the experimental value of r_0. A detailed discussion is given in the text. We also present results for the meson decay constants f_K and f_\pi and the \rho meson mass.