Semileptonic B Decays from an NRQCD/D234 Action
  Semileptonic B decays are studied on quenched anisotropic lattices using Symanzik improved glue, NRQCD heavy quark and D234 light quark actions. We employ constrained fits to extract ground state contributions to two- and three-point correlators. Results for the B --> pi, l nubar decay form factors are compared with previous lattice results. We find that our systematic errors (excluding quenching errors) are dominated by chiral extrapolation uncertainties. 
J. Shigemitsu, S. Collins, C.T.H. Davies, J. Hein, R.R. Horgan, G.P.   Lepage