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 Γ(B → πeν) is estimated to be 5%.