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

Abstract We discuss the computation of form factors for semi-leptonic decays of B-, B s -mesons in lattice QCD. Considering in particular the example of the static B s 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 V ub . The size of the corrections of order 1 / m b is just estimated at present but it is expected that their inclusion does not pose significant difficulties.