Extractions of |Vub|/|Vcb| from a combined study of the exclusive b-u(c)I-vI decays

Abstract

We have extracted the ratio |Vub|/|Vcb| from a combined study of the available inputs on B→(π,ρ,ω)ℓ-νℓ and B(Bs)→(D(∗),D(∗)s)ℓ−νℓ (ℓ=μ or e) decays. We have done our analysis with and without the inclusion of the available experimental results on the branching fraction BR(Bs→K+μ−νμ) or the ratio of the rates Γ(Bs→K+ℓ−νℓ)/Γ(Bs→D+sℓ−νℓ) . We have used all the available experimental data on the branching fractions in different q2-bins, the available theory inputs on the form factors from lattice and the light cone sum rule (LCSR) approach; analysed the data in different possible scenarios and presented the results. From a combined analysis of all the b → cℓ−νℓ exclusive decays, we have obtained |Vcb| = (40.5 ± 0.6) × 10−3 and from all the b → uℓ−νℓ modes, we obtain |Vub| = (3.46 ± 0.12) × 10−3 which changes to |Vub| = (3.51 ± 0.13) × 10−3 after dropping BR(Bs→K+μ−νμ). We hence report the values of the ratio |Vub|/|Vcb| = 0.085 ± 0.003 and 0.087 ± 0.003 with and without the input from Bs→K+μ−νμ modes, respectively. We have also predicted the ratio Γ(Bs→K+ℓ−νℓ)/Γ(Bs→D+s−νℓ) using the fit results. In addition, we provide the predictions of BR(Bs→K+μ−νμ) and BR(B→(ρ,ω)ℓ−νℓ) in the Standard Model (SM) in small q2-bins.