Continuum limit of the leading order HQET form factor in $B_s \to   K\ell\nu$ decays
  We discuss the computation of form factors for semi-leptonic decays of $\rm B$-, $\rm B_s$- mesons in lattice QCD. Considering in particular the example of the static $\rm B_s$ 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 $V_{\rm ub}$. The size of the corrections of order $1/m_{\rm b}$ is just estimated at present but it is expected that their inclusion does not pose significant difficulties. 
Felix Bahr, Debasish Banerjee, Fabio Bernardoni, Anosh Joseph, Mateusz   Koren, Hubert Simma, Rainer Sommer
hep-lat