Heavy--light decay constants in the continuum limit of quenched lattice QCD

TL;DR

This paper calculates heavy-light meson decay constants in quenched lattice QCD using the Schrödinger Functional and step scaling methods, providing continuum limit estimates for $f_{B_s}$ and $f_{D_s}$.

Contribution

It introduces a continuum extrapolation of decay constants in quenched lattice QCD using the step scaling method within the Schrödinger Functional framework, addressing the two-scale problem.

Findings

$f_{B_s} = 192(6)(4)$ MeV

$f_{D_s} = 240(5)(5)$ MeV

Effective continuum limit estimates for heavy-light decay constants

Abstract

We compute the decay constants for the heavy--light pseudoscalar mesons in the quenched approximation and continuum limit of lattice QCD. Within the Schrodinger Functional framework, we make use of the step scaling method, which has been previously introduced in order to deal with the two scale problem represented by the coexistence of a light and a heavy quark. The continuum extrapolation gives us a value $f_{B_s} = 192(6)(4)$ MeV for the $B_s$ meson decay constant and $f_{D_s} = 240(5)(5)$ MeV for the $D_s$ meson.