Model-independent description of B→ D πℓν decays

In this contribution we present a novel, model-independent description of semileptonic B→ D πℓν decays. In addition, we discuss recent developments in the understanding of coupled-channel D π-D η-D_s K S-wave scattering and, for the first time, apply them to semileptonic decays. We not only obtain model-independent predictions for kinematic distributions in B→ D πℓν decays, but also rule out the hypothesis that the gap between the inclusive B→ Xℓν branching fraction and the sum over exclusive channels is made up predominantly by B→ D^(∗)ηℓν decays.