Continuum limit of the leading-order HQET form factor in Bs → Kℓν decays

We discuss the computation of form factors for semi-leptonic decays of B-, BsBs-mesons in lattice QCD. Considering in particular the example of the static BsBs form factors we demonstrate that after non-perturbative renormalization the continuum limit can be taken with confidence. The resulting precision is of interest for extractions of VubVub. The size of the corrections of order 1/mb1/mb is just estimated at present but it is expected that their inclusion does not pose significant difficulties.