title: Standard model predictions for B→Kℓ(+)ℓ- with form factors from lattice QCD.
abstract: We calculate, for the first time using unquenched lattice QCD form factors, the standard model differential branching fractions dB/dq2(B→Kℓ(+)ℓ(-)) for ℓ=e, μ, τ and compare with experimental measurements by Belle, BABAR, CDF, and LHCb. We report on B(B→Kℓ(+)ℓ(-)) in q2 bins used by experiment and predict B(B→Kτ(+)τ(-))=(1.41±0.15)×10(-7). We also calculate the ratio of branching fractions R(e)(μ)=1.00029(69) and predict R(ℓ)(τ)=1.176(40), for ℓ=e, μ. Finally, we calculate the "flat term" in the angular distribution of the differential decay rate F(H)(e,μ,τ) in experimentally motivated q2 bins.
authors.affiliation: Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Bouchard
authors.forename: G Peter
authors.initials: GP
authors.lastname: Lepage
authors.forename: Christopher
authors.initials: C
authors.lastname: Monahan
authors.forename: Heechang
authors.initials: H
authors.lastname: Na
authors.forename: Junko
authors.initials: J
authors.lastname: Shigemitsu