Form factors of B -> pi l nu and a determination of vertical bar V-ub vertical bar with Mobius domain-wall fermions

Using a fully relativistic lattice fermion action, we compute the form factors of the semileptonic decay B -> pi l nu which is required for the determination of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-ub vertical bar. We employ the Mobius domain-wall fermion formalism for the generation of lattice ensembles with 2 + 1 sea quark flavors as well as for the valence heavy and light quarks. We compute the form factors at various values of the lattice spacing and multiple light and heavy quark masses, and extrapolate the results to the physical point. We combine our lattice results with the available experimental data to obtain vertical bar V-ub vertical bar = (3.93 +/- 0.41) x 10(-3).