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arXiv · 0902.4446

Penguins with Charm and Quark-Hadron Duality

M. Beneke·G. Buchalla·M. Neubert·C. T. Sachrajda
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Abstract

The integrated branching fraction of the process $B\to X_s l^+l^-$ is dominated by resonance background from narrow charmonium states, such as $B\to X_sψ\to X_s l^+l^-$, which exceeds the non-resonant charm-loop contribution by two orders of magnitude. The origin of this fact is discussed in view of the general expectation of quark-hadron duality. The situation in $B\to X_s l^+l^-$ is contrasted with charm-penguin amplitudes in two-body hadronic B decays of the type $B\toππ$, for which it is demonstrated that resonance effects and the potentially non-perturbative $c\bar c$ threshold region do not invalidate the standard picture of QCD factorization. This holds irrespective of whether the charm quark is treated as a light or a heavy quark.

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M. Beneke, G. Buchalla, M. Neubert, C. T. Sachrajda. 2009-02-25. Penguins with Charm and Quark-Hadron Duality. https://doi.org/10.1140/epjc/s10052-009-1028-9

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