Heavy quark scaling of $B\to \pi \ell \nu$ form factors with Möbius domain wall fermions

Abstract

We report on the progress of our calculation of form factors for the exclusive semileptonic decay of $B$ mesons to pions on $2+1$ flavour lattices with spacings from $0.080\mathrm{fm}$ down to $0.044\mathrm{fm}$. Using the Möbius domain wall fermion action for all quarks, we simulate pions with masses down to $230\mathrm{MeV}$ and extrapolate to the physical bottom quark mass by utilizing a range of heavy quark masses up to $2.44$ times the mass of the charm quark. We discuss the dependence on the pion mass, heavy quark mass and lattice spacing in our form factors results.

Comments: 7 pages, 6 figures, Talk presented at the 36th Annual International Symposium on Lattice Field Theory, 22-28 July 2018, Michigan State University, East Lansing, Michigan, USA