Accurate decay-constant ratios fB*/fB and fB*s/fBs from Borel QCD sum rules.

We present our analysis of the decay constants of the beauty vector mesons B* and B*s within the framework of dispersive sum rules for the two-point correlator of vector currents in QCD. While the decay constants of the vector mesons fB* and fB*s--similar to the decay constants of the pseudoscalar mesons fB and fBs--individually have large uncertainties induced by theory parameters not known with a satisfactory precision, these uncertainties almost entirely cancel out in the ratios of vector over pseudoscalar decay constants. These ratios, thus, may be predicted with very high accuracy due to the good control over the systematic uncertainties of the decay constants gained upon application of our hadron-parameter extraction algorithm. Our final results read fB*/fB=0.944±0.011OPE±0.018syst and fB*s/fBs=0.947±0.023OPE±0.020syst. Thus, both fB*/fB and fB*s/fBs are less than unity at 2.5s and 2s level, respectively. [ABSTRACT FROM AUTHOR]