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arXiv · hep-ph/0105217

Improved Determination of |V_{ub}| from Inclusive Semileptonic B-Meson Decays

Matthias Neubert·Thomas Becher
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Abstract

We reduce the perturbative uncertainty in the determination of |V_{ub}| from inclusive semileptonic B decays by calculating the rate of B -> X_u l nu events with dilepton invariant mass q^2>(M_B-M_D)^2 at subleading order in the hybrid expansion, and to next-to-leading order in renormalization-group improved perturbation theory. We also resum logarithmic corrections to the leading power-suppressed contributions. Studying the effect of different b-quark mass definitions we find that the branching ratio after the cut is Br(B -> X_u l nu)=(20.9+-4.0)|V_{ub}|^2, where the dominant error is due to the uncertainty in the b-quark mass. This implies that |V_{ub}| can be determined with a precision of about 10%.

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Matthias Neubert, Thomas Becher. 2001-05-22. Improved Determination of |V_{ub}| from Inclusive Semileptonic B-Meson Decays. https://doi.org/10.1016/s0370-2693(02)01760-4

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