Bs → Klvl and B(s) → π (K)l+l- decays at large recoil and CKM matrix elements

We provide hadronic input for the B-meson semileptonic transitions to a light pseudoscalar meson at large recoil. The B-s -> K form factor calculated from QCD light-cone sum rule is updated, to be used for a vertical bar V-ub vertical bar determination from the B-s -> Klv width. Furthermore, we calculate the hadronic input for the binned observables of B -> pi l(+)l(-) and B -> Kl(+)l(-). In addition to the form factors, the nonlocal hadronic matrix elements are obtained, combining QCD factorization and light-cone sum rules with hadronic dispersion relations. We emphasize that, due to nonlocal effects, the ratio of branching fractions of these decays is not sufficient for an accurate extraction of the vertical bar V-td/V-ts vertical bar ratio. Instead, we suggest to determine the Wolfenstein parameters A, rho, eta of the CKM matrix, combining the branching fractions of B -> Kl(+)l(-) and B -> pi l(+)l(-) with the direct CP-asymmetry in the latter decay. We also obtain the hadronic matrix elements for a yet unexplored channel B-s -> Kl(+)l(-).