Improved QCD Sum-Rule Approach to Heavy-Meson Decay Constants

TL;DR

This paper enhances the QCD sum-rule method to more accurately determine heavy-meson decay constants by refining the treatment of hadron excitations and continuum, focusing on reducing uncertainties in the calculations.

Contribution

It introduces a more sophisticated approach to the QCD sum-rule framework, improving the extraction of heavy-light meson decay constants using the running heavy-quark mass.

Findings

Improved accuracy in decay constant extraction.

Better control over systematic uncertainties.

Enhanced convergence of perturbative expansion.

Abstract

A visible improvement of the QCD sum-rule framework, achieved only recently by a slightly more sophisticated consideration of the hadron excitations and continuum, is applied to the extraction of the decay constants of heavy-light pseudoscalar mesons from two-point correlators of heavy-light pseudoscalar currents. This analysis is carried out entirely in terms of the running heavy-quark mass, for which the perturbative expansion exhibits a passable convergence. Our main concern is to gain control over both statistical and systematic uncertainties of the extracted decay constants, the former being induced by the QCD parameter values requested for input, the latter arising from the intrinsically limited accuracy of the QCD sum-rule techniques.