Quenched Heavy-Light Decay Constants

TL;DR

This paper reports lattice QCD calculations of heavy-light decay constants using improved actions and static approximation, providing results consistent across different lattice parameters and comparing Wilson and improved actions to assess systematic effects.

Contribution

It presents new lattice QCD results for heavy-light decay constants using both propagating and static quarks, including a comparison of Wilson and improved actions at different lattice spacings.

Findings

Decay constants for D and B mesons are consistent with previous studies.

Static approximation yields a specific value for f_B^stat.

Results are consistent across different lattice spacings and actions.

Abstract

We present results for heavy-light decay constants, using both propagating quarks and the static approximation, in O(a)-improved, quenched lattice QCD. At beta=6.2 on a 24^3x48 lattice we find f_D=185 +4-3(stat)+42-7(syst) MeV, f_B=160 +6-6 +53-19 MeV, f_{D_s}/f_D=1.18 +2-2 and f_{B_s}/f_B=1.22 +4-3, in good agreement with earlier studies. From the static theory we obtain f_B^stat=253 +16-15 +105-14 MeV. We also present results from a simulation at beta=6.0 on a 16^3x48 lattice, which are consistent with those at beta=6.2. In order to study the effects of improvement, we present a direct comparison of the results using both the Wilson and the improved action at beta=6.0.