Decay constants of B and D mesons from non-perturbatively improved lattice QCD

Abstract

The decay constants of B, D and K mesons are computed in quenched lattice QCD at two different values of the coupling. The action and operators are O(a) improved with non-perturbative coefficients. The results are f B = 195(6) +24 −23 MeV, f D = 206(4) +17 −10 MeV, f Bs = 220(6) +23 −28 MeV, f Ds = 229(3) +23 −12 MeV and f K = 150(3) +12 − 8MeV. Systematic errors are discussed in detail. Results for vector decay constants, flavour symmetry breaking ratios of decay constants, the pseudoscalar-vector mass splitting and D meson masses are also presented.

B meson decay constants f B c $$ {f}_{B_c} $$ , f B s $$ {f}_{B_s} $$ and f B from QCD sum rules

“…Sum rule calculations of the decay constants have been performed since the 1980's, with results in the range f B = 160 − 230 MeV, f Bs /f B = 1.1 − 1.4, and f Bc = 160 − 360 MeV [3]- [11]. A heavy quark effective theory calculation [12] gives f B = 206 ± 20 MeV, while historical LQCD determinations fall in the wide range f B = 161 − 218 MeV, and f Bs /f B = 1.11 − 1.16 [13][14][15]. Recent…”

Analysis of Vertex D * D * ρ with Light-Cone QCD Sum Rules

“…The central value of the decay constant f D * from lattice simulation is about f D * = 0.23GeV [12].…”

Enhancement ofB(Bd→μ+μ−Bobeth1, Ewerth2, Krüger3 et al. 2002Phys. Rev. D1075800View full textAdd to dashboardCite

“…We note that the main uncertainty on the branching ratio in Eq. (1.1) arises from f Bs , with a typical value of (230 ± 30) MeV obtained from lattice QCD calculations [3]. On the other hand, the relative rates ofB d andB s decays [Eq.…”