$B_s \to K\ell\nu$ form factors from lattice QCD with domain-wall heavy quarks

TL;DR

This study uses lattice QCD with domain-wall quarks to compute form factors for the $B_s o K\,\ell\nu$ decay, providing preliminary results that aid understanding of semileptonic B-meson decays.

Contribution

It introduces a fully relativistic lattice QCD approach with domain-wall quarks for calculating $B_s o K\,\ell\nu$ form factors, controlling discretization errors at high quark masses.

Findings

Preliminary form factor results obtained from correlator ratios.

Use of relativistic M"obius domain-wall action for all quark flavors.

Lattice cutoff set at approximately 2.5 GeV.

Abstract

We report on our on-going study of the $B_s \to K\ell\nu$ decay in $N_f=2+1$ lattice QCD. We employ fully relativistic setup in which the M\"obius domain-wall action is used for all quark flavors. The lattice cutoff is $a^{-1} \sim 2.5$ GeV, where we take bottom quark masses up to $m_Q\!<\!0.7a^{-1}$ in order to control discretization errors. We present preliminary results for the relevant form factors extracted from correlator ratios by inspecting their ground state saturation.