title: B→πll Form Factors for New Physics Searches from Lattice QCD.
abstract: The rare decay B→πℓ^{+}ℓ^{-} arises from b→d flavor-changing neutral currents and could be sensitive to physics beyond the standard model. Here, we present the first ab initio QCD calculation of the B→π tensor form factor f_{T}. Together with the vector and scalar form factors f_{+} and f_{0} from our companion work [J. A. Bailey et al., Phys. Rev. D 92, 014024 (2015)], these parametrize the hadronic contribution to B→π semileptonic decays in any extension of the standard model. We obtain the total branching ratio BR(B^{+}→π^{+}μ^{+}μ^{-})=20.4(2.1)×10^{-9} in the standard model, which is the most precise theoretical determination to date, and agrees with the recent measurement from the LHCb experiment [R. Aaij et al., J. High Energy Phys. 12 (2012) 125].
authors.affiliation: Department of Physics and Astronomy, Seoul National University, Seoul 08826, South Korea.
authors.forename: Jon A
authors.initials: JA
authors.lastname: Bailey
authors.affiliation: Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA.
authors.forename: A
authors.initials: A
authors.lastname: Bazavov
authors.affiliation: Department of Physics, Washington University, St. Louis, Missouri 63130, USA.
authors.forename: C
authors.initials: C
authors.lastname: Bernard
authors.affiliation: Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Bouchard
authors.affiliation: Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: C
authors.initials: C
authors.lastname: DeTar
authors.affiliation: Department of Physics, Syracuse University, Syracuse, New York 13244, USA.
authors.forename: Daping
authors.initials: D
authors.lastname: Du
authors.affiliation: Department of Physics, University of Illinois, Urbana, Illinois 61801, USA.
authors.forename: A X
authors.initials: AX
authors.lastname: El-Khadra
authors.affiliation: Liberal Arts Department, School of the Art Institute of Chicago, Chicago, Illinois 60603, USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Freeland
authors.affiliation: CAFPE and Departamento de Fisica Teórica y del Cosmos, Universidad de Granada, E-18002 Granada, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Gámiz
authors.affiliation: Department of Physics, Indiana University, Bloomington, Indiana 47405, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Gottlieb
authors.affiliation: American Physical Society, Ridge, New York 11961, USA.
authors.forename: U M
authors.initials: UM
authors.lastname: Heller
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.|Institute for Advanced Study, Technische Universität München, 85748 Garching, Germany.
authors.forename: A S
authors.initials: AS
authors.lastname: Kronfeld
authors.affiliation: Department of Physics, Syracuse University, Syracuse, New York 13244, USA.
authors.forename: J
authors.initials: J
authors.lastname: Laiho
authors.affiliation: Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: L
authors.initials: L
authors.lastname: Levkova
authors.affiliation: Department of Physics, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Yuzhi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Physics, Indiana University, Bloomington, Indiana 47405, USA.
authors.forename: E
authors.initials: E
authors.lastname: Lunghi
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: P B
authors.initials: PB
authors.lastname: Mackenzie
authors.affiliation: Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Meurice
authors.affiliation: Department of Physics, University of Colorado, Boulder, Colorado 80309, USA.|RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973, USA.
authors.forename: E
authors.initials: E
authors.lastname: Neil
authors.affiliation: Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: Si-Wei
authors.initials: SW
authors.lastname: Qiu
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: J N
authors.initials: JN
authors.lastname: Simone
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106, USA.
authors.forename: R
authors.initials: R
authors.lastname: Sugar
authors.affiliation: Physics Department, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: D
authors.initials: D
authors.lastname: Toussaint
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Van de Water
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: Ran
authors.initials: R
authors.lastname: Zhou
mesh_terms: D004601:Elementary Particles; D008962:Models, Theoretical; D009686:Nuclear Physics; D011522:Protons
chemical_list: D011522:Protons