Improved fD(s)∗, fB(s)∗ and fBc from QCD Laplace sum rules

Abstract

Anticipating future precise measurements of the D- and B-like (semi)leptonic and hadronic decays for alternative determinations of the CKM mixing angles, we pursue our program on the D- and B-like mesons by improving the estimates of [Formula: see text] and [Formula: see text] (analogue to [Formula: see text]) by using the well-established (inverse) Laplace sum rules (LSR) and/or their suitable ratios less affected by the systematics, which are known to N2LO pQCD and where the complete [Formula: see text] nonperturbative condensate contributions are included. The convergence of the PT series is analyzed by an estimate of the N3LO terms based on geometric growth of the coefficients. In addition to the standard LSR variable [Formula: see text] and the QCD continuum threshold [Formula: see text] stability criteria, we extract our optimal results by also requiring stability on the variation of the arbitrary QCD subtraction point [Formula: see text] which reduces the errors in the analysis. We complete the study of the open bottom states by an estimate of [Formula: see text]. Our results summarized in Tables 3 and 4 are compared with some other recent sum rules and lattice estimates.