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arXiv · hep-ex/0408045

Determination of |Vub| in inclusive semileptonic B meson decays

B. Aubert·The BaBar Collaboration
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Abstract

We present a preliminary determination of the CKM matrix element |Vub| based on the analysis of semileptonic B decays from a sample of 88 million Upsilon(4S) decays collected with the BaBar detector at the e+e- storage ring. Charmless semileptonic B decays are selected using the electron energy E_e and the invariant mass q^2 of the electron-neutrino pair. The neutrino momentum is inferred from a measurement of the visible energy and momentum in the detector and knowledge of the e+e- beam momenta. The partial branching fraction is determined in a region of the q^2-E_e plane where semileptonic B decays to charm are highly suppressed. The total charmless semileptonic branching fraction is extracted using a theoretical calculation based on the heavy quark expansion. Preliminary results yield |Vub| = (4.57 +/- 0.21 +/- 0.25 +/- 0.34 +0.59/-0.29 +/- 0.22) x 10^{-3} where the uncertainties are from statistics (data and MC), detector modeling, background modeling, the shape function, and the heavy quark operator product expansion, respectively.

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B. Aubert, The BaBar Collaboration. 2004-08-12. Determination of |Vub| in inclusive semileptonic B meson decays. https://arxiv.org/abs/hep-ex/0408045

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