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

Abstract

We report on our calculation of the B \to D^(*) \ell \nu form factors in 2+1 flavor lattice QCD. The Möbius 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.

Comments: 7 pages, 4 figures, talk presented at the 37th International Symposium on Lattice Field Theory (Lattice2019), 16-22 June 2019, Wuhan, China