Semi-leptonic decays of heavy mesons and the Isgur–Wise function in quenched lattice QCD

Abstract The form factors for the semi-leptonic B→D and B→D ∗ decays are evaluated in quenched lattice QCD at two different values of the coupling, β=6.0 and 6.2. The action and the operators are fully O (a) non-perturbatively improved. The slope of the Isgur–Wise function is evaluated, and found to be ρ2=0.83+15+24−11−22 (quoted errors are statistical and systematic, respectively). Ratios of form factors are evaluated and compared to experimental determinations.