B→πlν semileptonic form factor from three-flavor lattice QCD: A model-independent determination of |Vub|

Jon A. Bailey, C. Bernard, C. Detar, M. Di Pierro, A. X. El-Khadra, R. T. Evans, E. D. Freeland, E. Gamiz, Steven Gottlieb, U. M. Heller, J. E. Hetrick, A. S. Kronfeld, John W Laiho, L. Levkova, P. B. MacKenzie, M. Okamoto, J. N. Simone, R. Sugar, D. Toussaint, R. S. Van De Water

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Abstract

We calculate the form factor f+(q2) for B-meson semileptonic decay in unquenched lattice QCD with 2+1 flavors of light sea quarks. We use Asqtad-improved staggered light quarks and a Fermilab bottom quark on gauge configurations generated by the MILC Collaboration. We simulate with several light-quark masses and at two lattice spacings, and extrapolate to the physical quark mass and continuum limit using heavy-light meson staggered chiral perturbation theory. We then fit the lattice result for f+(q2) simultaneously with that measured by the BABAR experiment using a parameterization of the form-factor shape in q2, which relies only on analyticity and unitarity in order to determine the Cabibbo-Kobayashi-Maskawa matrix element |Vub|. This approach reduces the total uncertainty in |Vub| by combining the lattice and experimental information in an optimal, model-independent manner. We find a value of |Vub|×103=3.38±0.36.

Original languageEnglish (US)
Article number054507
JournalPhysical Review D
Volume79
Issue number5
DOIs
StatePublished - Mar 2 2009
Externally publishedYes

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ASJC Scopus subject areas

  • Nuclear and High Energy Physics

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Bailey, J. A., Bernard, C., Detar, C., Di Pierro, M., El-Khadra, A. X., Evans, R. T., Freeland, E. D., Gamiz, E., Gottlieb, S., Heller, U. M., Hetrick, J. E., Kronfeld, A. S., Laiho, J. W., Levkova, L., MacKenzie, P. B., Okamoto, M., Simone, J. N., Sugar, R., Toussaint, D., & Van De Water, R. S. (2009). B→πlν semileptonic form factor from three-flavor lattice QCD: A model-independent determination of |Vub|. Physical Review D, 79(5), [054507]. https://doi.org/10.1103/PhysRevD.79.054507