We provide results for the full set of form factors describing semileptonic Bmeson transitions to pseudoscalar mesons π, K,D and vector mesons ρ, K * ,D * . Our results are obtained within the framework of QCD Light-Cone Sum Rules with B-meson distribution amplitudes. We recalculate and confirm the results for the leading-twist twoparticle contributions in the literature. Furthermore, we calculate and provide new expressions for the two-particle contributions up to twist four. Following new developments for the three-particle distribution amplitudes, we calculate and provide new results for the complete set of three-particle contributions up to twist four. The form factors are computed numerically at several phase space points using up-to-date input parameters, including correlations across phase space points and form factors. We use a model ansatz for all contributing B-meson distribution amplitudes that is self-consistent up to twistfour accuracy. We find that the higher-twist two-particle contributions have a substantial impact on the results, and dominate over the three-particle contributions. Our numerical results, including correlations, are provided as machine-readable ancillary files. We discuss the qualitative phenomenological impact of our results on the present b anomalies.

We revisit the theoretical predictions and the parametrization of non-local matrix elements in rare $$ {\overline{B}}_{(s)}\to \left\{{\overline{K}}^{\left(\ast \right)},\phi \right\}{\mathrm{\ell}}^{+}{\mathrm{\ell}}^{-} $$ B ¯ s → K ¯ ∗ ϕ ℓ + ℓ − and $$ {\overline{B}}_{(s)}\to \left\{{\overline{K}}^{\ast },\phi \right\}\gamma $$ B ¯ s → K ¯ ∗ ϕ γ decays. We improve upon the current state of these matrix elements in two ways. First, we recalculate the hadronic matrix elements needed at subleading power in the light-cone OPE using B-meson light-cone sum rules. Our analytical results supersede those in the literature. We discuss the origin of our improvements and provide numerical results for the processes under consideration. Second, we derive the first dispersive bound on the non-local matrix elements. It provides a parametric handle on the truncation error in extrapolations of the matrix elements to large timelike momentum transfer using the z expansion. We illustrate the power of the dispersive bound at the hand of a simple phenomenological application. As a side result of our work, we also provide numerical results for the Bs → ϕ form factors from B-meson light-cone sum rules.

We carry out a comprehensive analysis of the full set ofBq → D ( * ) q form factors for spectator quarks q = u, d, s within the framework of the Heavy-Quark Expansion (HQE) to order O αs, 1/m b , 1/m 2 c . In addition to the available lattice QCD calculations we make use of two new sets of theoretical constraints: we produce for the first time numerical predictions for the full set ofBs → D ( * ) s form factors using Light-Cone Sum Rules with Bs-meson distribution amplitudes. Furthermore, we reassess the QCD three-point sum rule results for the Isgur-Wise functions entering all our form factors for both q = u, d and q = s spectator quarks. These additional constraints allow us to go beyond the commonly used assumption of SU (3)F symmetry for theBs → D ( * ) s form factors, especially in the unitarity constraints which we impose throughout our analysis. We find the coefficients of the IW functions emerging at O 1/m 2 c to be consistent with the naive O (1) expectation, indicating a good convergence of the HQE. While we do not find significant SU (3) breaking, the explicit treatment of q = s as compared to a simple symmetry assumption renders the unitarity constraints more effective. We find that the (pseudo)scalar bounds are saturated to a large degree, which affects our theory predictions. We analyze the phenomenological consequences of our improved form factors by extracting |V cb | fromB → D ( * ) ν decays and producing theoretical predictions for the lepton-flavour universality ratios R(D), R(D * ), R(Ds) and R(D * s ), as well as the τ -and D * q polarization fractions for theBq → D ( * ) q τ ν modes.