$B\!\to\!D^{(*)}\ell\nu$ form factors from lattice QCD with relativistic heavy quarks

TL;DR

This study calculates B to D(*) semileptonic form factors using 2+1 flavor lattice QCD with relativistic heavy quarks, providing precise results for phenomenological applications.

Contribution

First lattice QCD calculation of B to D(*) form factors employing relativistic heavy quarks and multiple lattice spacings for improved accuracy.

Findings

Form factors extrapolated to physical quark masses and continuum limit.

Results consistent with recent phenomenological analyses.

Controlled discretization errors up to 4.5 GeV lattice cutoff.

Abstract

We report on our calculation of the B \to D^(*) \ell \nu form factors in 2+1 flavor lattice QCD. The M\"obius domain-wall action is employed for light, strange, charm and bottom quarks. At lattice cutoffs 1/a \sim 2.4, 3.6 and 4.5 GeV, we simulate bottom quark masses up to 0.7/a to control discretization errors. The pion mass is as low as 230 MeV. We extrapolate the form factors to the continuum limit and physical quark masses, and make a comparison with recent phenomenological analyses.