Measurement of the Inclusive Semileptonic Branching Fraction of B Mesons Using Fully Reconstructed B-Mesons as Tags in the BABAR Experiment

Measurement of the Inclusive Semileptonic Branching Fraction of B Mesons Using Fully Reconstructed B-Mesons as Tags in the BABAR Experiment

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Published: 2004

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The BABAR experiment at SLAC provides an opportunity for measurement of the Standard Model parameters describing CP violation. A method of measuring the CKM matrix element V[sub cb] using Inclusive Semileptonic B decays in events tagged by a fully reconstructed decay of one of the B mesons is presented here. This mode is considered to be one of the most powerful approaches due to its large branching fraction, simplicity of the theoretical description and very clean experimental signatures. Using fully reconstructed B mesons to flag B[bar B] event we were able to produce the spectrum and branching fraction for electron momenta P[sub C.M.S.]> 0.5 GeV/c. Extrapolation to the lower momenta has been carried out with Heavy Quark Effective Theory. The branching fractions are measured separately for charged and neutral B mesons. For 82 fb[sup -1] of data collected at BABAR we obtain: BR(B[sup [+-]] [yields] X e[bar [nu]]) = 10.63 [+-] 0.24 [+-] 0.29%, BR(B[sup 0] [yields] X e[bar [nu]]) = 10.68 [+-] 0.34 [+-] 0.31%, averaged BR(B [yields] X e[bar [nu]]) = 10.65 [+-] 0.19 [+-] 0.27%, ratio of Branching fractions BR(B[sup [+-]])/BR(B[sup 0]) = 0.996 [+-] 0.039 [+-] 0.015 (errors are statistical and systematic, respectively). They also obtain V[sub cb] = 0.0409 [+-] 0.00074 [+-] 0.0010 [+-] 0.000858 (errors are: statistical, systematic and theoretical).


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.


Lepton And Photon Interactions At High Energies: Lepton-photon 2003 - Proceedings Of The Xxi International Symposium

Lepton And Photon Interactions At High Energies: Lepton-photon 2003 - Proceedings Of The Xxi International Symposium

Author: Harry W K Cheung

Publisher: World Scientific

Published: 2004-02-20

Total Pages: 575

ISBN-13: 9814483516

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This volume contains contributions to the XXI International Symposium on Lepton and Photon Interactions at High Energies, held at the Fermi National Accelerator Laboratory. It gives up-to-date reviews of all aspects of particle physics, written by leading practitioners in the field. The review nature of all the articles makes this volume more accessible to students and researchers in other fields of physics. In addition to new experimental data and advances in theory, the future directions and prospects for the field are covered.The proceedings have been selected for coverage in:• Index to Scientific & Technical Proceedings® (ISTP® / ISI Proceedings)• Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)• CC Proceedings — Engineering & Physical Sciences


Lepton and Photon Interactions at High Energies

Lepton and Photon Interactions at High Energies

Author: Harry W. K. Cheung

Publisher: World Scientific

Published: 2004

Total Pages: 575

ISBN-13: 9812387161

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This volume contains contributions to the XXI International Symposium on Lepton and Photon Interactions at High Energies, held at the Fermi National Accelerator Laboratory. It gives up-to-date reviews of all aspects of particle physics, written by leading practitioners in the field. The review nature of all the articles makes this volume more accessible to students and researchers in other fields of physics. In addition to new experimental data and advances in theory, the future directions and prospects for the field are covered.The proceedings have been selected for coverage in: ? Index to Scientific & Technical Proceedings? (ISTP? / ISI Proceedings)? Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)? CC Proceedings ? Engineering & Physical Sciences


Inclusive Semileptonic B Decays at BABAR.

Inclusive Semileptonic B Decays at BABAR.

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Published: 2002

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We present measurements of the inclusive semileptonic branching fractions of charged and neutral B mesons using 20.6 fb[sup -1] of data measured at the[Upsilon](4S) with the BABAR detector. Events are tagged with a fully reconstructed hadronic decay of a B meson. The correlation between the flavor of the tag B meson and the electron charge allows the separation of prompt semileptonic B decays and cascade semileptonic charm decays. We obtain the preliminary inclusive semileptonic branching fraction of charged B mesons b[sub+]= 0.103[+-] 0.006[+-] 0.005, neutral B mesons b[sub 0]= 0.104[+-] 0.008[+-] 0.005, their average b= 0.104[+-] 0.005[+-] 0.004, and their ratio b[sub+]/b[sub 0]= 0.99[+-] 0.10[+-] 0.03.


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].


Semileptonic B Decays at BaBar

Semileptonic B Decays at BaBar

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Published: 2007

Total Pages: 5

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We present measurements of the inclusive semileptonic branching fractions of charged and neutral B mesons using 20.6 fb-1 of data measured at the Upsilon(4S) with the BABAR detector. Events are tagged with a fully reconstructed hadronic decay of a B meson. The correlation between the flavor of the tag B meson and the electron charge allows the separation of prompt semileptonic B decays and cascade semileptonic charm decays. We obtain the preliminary inclusive semileptonic branching fraction of charged B mesons b+ = 0.103+/-0.006+/-0.005, neutral B mesons b0 = 0.104+/-0.008+/-0.005, their average b = 0.104+/-0.005+/-0.004, and their ratio b+/b0 = 0.99+/-0.10+/-0.03.


Fundamental Interactions - Proceedings Of The 22nd Lake Louise Winter Institute

Fundamental Interactions - Proceedings Of The 22nd Lake Louise Winter Institute

Author: Alan Astbury

Publisher: World Scientific

Published: 2007-12-28

Total Pages: 487

ISBN-13: 9814472506

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This proceedings volume contains the latest results from the field of particle physics. The contributions cover the current status of all the Large Hadron Collider (LHC) experiments, the implications of the LHC for cosmology, and the search for dark matter and nuclear astrophysics. It also includes work on the current status of the future International Linear Collider (ILC).