B meson decay constants f B c fBc , f B s fBₛ and f B from QCD sum rules

Finite energy QCD sum rules with Legendre polynomial integration kernels are used to determine the heavy meson decay constant fBc , and revisit f B and fBₛ . Results exhibit excellent stability in a wide range of values of the integration radius in the complex squared energy plane, and of the order of the Legendre polynomial. Results are fBc = 528 ± 19 MeV, f B = 186 ± 14 MeV, and fBₛ = 222 ± 12 MeV.