Erratum:Bs→Ds/B→Dsemileptonic form-factor ratios and their application toBR(Bs0→μ+μ−)[Phys. Rev. D85, 114502 (2012)

Abstract

We calculate form-factor ratios between the semileptonic decays {bar B}{sup 0} {yields} D{sup +} {ell}{sup -}{bar {nu}} and {bar B}{sub s}{sup 0} {yields} D{sub s}{sup +}{ell}{sup -}{bar {nu}} with lattice QCD. These ratios are a key theoretical input in a new strategy to determine the fragmentation fractions of the neutral B decays, which are needed for measurements of BR(B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -}). They use the MILC ensembles of gauge configurations with 2 + 1 flavors of sea quarks at two lattice spacings of approximately 0.12 fm and 0.09 fm. We use the model-independent z parametrization to extrapolate their simulation results at small recoil toward maximum recoil. The results for the form-factor ratios are {line_integral}{sub 0}{sup (s)} (M{sub {pi}}{sup 2})/{line_integral}{sub 0}{sup (d)} (M{sub K}{sup 2}) = 1.046(44){sub stat.}(15){sub syst.} and {line_integral}{sub 0}{sup (s)} (M{sub {pi}}{sup 2})/{line_integral}{sub 0}{sup (d)} (M{sub {pi}}{sup 2}) = 1.054(47){sub stat.}(17){sub syst.}. In contrast to a QCD sum-rule calculation, no significant departure from U-spin (d {leftrightarrow} s) symmetry is observed.