A bstract Recent work on B → π, K and B → D form factors from lattice QCD and light-cone sum rules has made it possible to constrain the inverse moment λ B of the B -meson light-cone distribution amplitudes by performing a global fit of B → π, K, D form factors. We have compiled the B → π, K, D form factors calculated by the HPQCD, MILC, and RBC/UKQCD collaborations in the large q 2 region. By employing an three-parameter ansatz of the B -meson light-cone distribution amplitudes, we express the B → π, K, D form factors at q 2 = 0 that are calculated from light-cone sum rules, in terms of the inverse moment λ B of the leading-twist B -meson light-cone distribution amplitude. In the B → πℓν channel, we also include the available q 2 -binned experimental data from the BaBar, Belle, and Belle II collaborations. Using the Bourrely-Caprini-Lellouch parametrization, we perform a global fit and obtain λ B = 217 (19) -₁₇^+82 217 19 − 17 + 82 MeV and | V ub | = 3. 68 (13) -₁^+0 3. 68 13 − 1 + 0 × 10 −3. The second uncertainty is obtained by constraining λ B > 200 MeV and varying the inverse logarithmic moments ₁ σ ̂ 1 ∈ −0. 7, 0. 7 and ₂ σ ̂ 2 ∈ −6, 6, which represents the model-dependent uncertainty from the B -meson light-cone distribution amplitudes. When taking into account λ B and ₁ σ ̂ 1 as fitting parameters simultaneously, the intervals of our preditions are λ B = 208, 324 MeV and ₁ σ ̂ 1 = −0. 7, 0. 27.
Li et al. (Tue,) studied this question.