Measurement of the Inclusive Charmless Semileptonic Branching Ratio of B Mesons and Determination Of[verticalV[sub Ub][vertical
Measurement of the Inclusive Charmless Semileptonic Branching Ratio of B Mesons and Determination Of[verticalV[sub Ub][vertical

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Published: 2003

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We report a measurement of the inclusive charmless semileptonic branching fraction of B mesons in a sample of 89 million B[bar B] events recorded with the BABAR detector at the[Upsilon](4S) resonance. Events are selected by fully reconstructing the decay of one B meson and identifying a charged lepton from the decay of the other B meson. The number of signal events is extracted from the hadronic mass distribution and is used to determine the ratio of branching fractions[Beta]([bar B][yields] X[sub u]l[bar[nu]])/[Beta]([bar B][yields] Xl[bar[nu]])= (2.06[+-] 0.25(stat)[+-] 0.23(syst)[+-] 0.36(theo)) x 10[sup -2]. Using the measured branching fraction for inclusive semileptonic B decays, we find[Beta]([bar B][yields] X[sub u]l[bar[nu]])= (2.24[+-] 0.27(stat)[+-] 0.26(syst)[+-] 0.39(theo)) x 10[sup -3] and derive the CKM matrix elementV[sub ub]= (4.62[+-] 0.28(stat)[+-] 0.27(syst)[+-] 0.48(theo)) x 10[sup -3].

Measurement of the Inclusive Charmless Semileptonic Branching Ratio of B Mesons and Determination of
Measurement of the Inclusive Charmless Semileptonic Branching Ratio of B Mesons and Determination of

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Published: 2003

Total Pages: 7

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We report a measurement of the inclusive charmless semileptonic branching fraction of B mesons in a sample of 89 million B{bar B} events recorded with the BABAR detector at the [Upsilon](4S) resonance. Events are selected by fully reconstructing the decay of one B meson and identifying a charged lepton from the decay of the other B meson. The number of signal events is extracted from the hadronic mass distribution and is used to determine the ratio of branching fractions [Beta]({bar B} → X{sub u}l{bar {nu}})/[Beta]({bar B} → Xl{bar {nu}}) = (2.06 ± 0.25(stat) ± 0.23(syst) ± 0.36(theo)) x 10−2. Using the measured branching fraction for inclusive semileptonic B decays, we find [Beta]({bar B} → X{sub u}l{bar {nu}}) = (2.24 ± 0.27(stat) ± 0.26(syst) ± 0.39(theo)) x 10−3 and derive the CKM matrix element.

Measurement of Partial Branching Fractions of Inclusive Charmless B Meson Decays to K, K0, and Pi
Measurement of Partial Branching Fractions of Inclusive Charmless B Meson Decays to K, K0, and Pi

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Published: 2011

Total Pages: 8

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The authors present measurements of partial branching fractions of B 2!KX, B 2!K° X, and B 2![pi]+X, where X denotes any accessible final state above the endpoint for B decays to charmed mesons, specifically for momenta of the candidate hadron greater than 2.34 (2.36) GeV for kaons (pions) in the B rest frame. These measurements are sensitive to potential new-phisics particles which could enter the b 2!s(d) loop transitions. The analysis is performed on a data sample consisting of 383 x 106 B{bar B} pairs collected with the BABAR detector at the PEP-II e+e− asymmetric energy collider. The results are in agreement with standard model predictions and exclude large enhancements of the inclusive branching fraction due to sources of new physics.

Measurement of the Branching Fraction for Inclusive Semileptonic B Meson Decays
Measurement of the Branching Fraction for Inclusive Semileptonic B Meson Decays

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Published: 2003

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A largely model-independent measurement of the inclusive electron momentum spectrum and branching fraction for semileptonic decays of B mesons is presented based on data recorded at the[Upsilon](4S) resonance with the BABAR detector. Backgrounds from secondary charm decays are separated from prompt B decays using charge and angular correlations between the electron from one B meson and a high momentum electron tag from the second B meson. The resulting branching fraction is[Beta](B[yields] Xe[nu])= (10.87[+-] 0.18(stat)[+-] 0.30(syst))%. Based on this measurement we determine the CKM matrix elementV[sub cb].