B → π, K, η Decay Formfactors from Light-Cone Sum Rules

We present an improved calculation of all B -> light pseudoscalar formfactors from light-cone sum rules, including one-loop radiative corrections to twist-2 and twist-3 contributions, and leading order twist-4 corrections. The total theoretical uncertainty of our results at zero momentum transfer is 10 to 13%. The dependence of the formfactors on the momentum transfer q^2 is parametrized in a simple way that is consistent with their analytical properties and is valid for all physical q^2. The uncertainty of the extrapolation in q^2 on the semileptonic decay rate Gamma(B -> pi e nu) is estimated to be 5%.