Form factors in the $\mathrm{B}_\mathrm{s} \rightarrow \mathrm{K} \ell \nu$ decays using HQET and the lattice

Abstract

We report on a recent computation of the form factors in semi-leptonic decays of the $\mathrm{B}_\mathrm{s}$ using Heavy Quark Effective Theory (HQET) formalism applied on the lattice. The connection of the form factors with the 2-point and 3-point correlators on the lattice is explained, and the subsequent non-perturbative renormalization of HQET and it's matching to $N_f=2$ QCD is outlined. The results of the (static) leading-order calculation in the continuum limit is presented.