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Precision Global Determination of the B→X_{s}γ Decay Rate
Florian U Bernlochner1, Heiko Lacker2, Zoltan Ligeti3
1Physikalisches Institut, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53113 Bonn, Germany.
Abstract:
We perform the first global fit to inclusive B→X_{s}γ measurements using a model-independent treatment of the nonperturbative b-quark distribution function, with next-to-next-to-leading logarithmic resummation and O(α_{s}^{2}) fixed-order contributions. The normalization of the B→X_{s}γ decay rate, given by |C_{7}^{incl}V_{tb}V_{ts}^{*}|^{2}, is sensitive to physics beyond the standard model (SM). We determine |C_{7}^{incl}V_{tb}V_{ts}^{*}|=(14.77±0.51_{fit}±0.59_{theory}±0.08_{param})×10^{-3}, in good agreement with the SM prediction, and the b-quark mass m_{b}^{1S}=(4.750±0.027_{fit}±0.033_{theory}±0.003_{param}) GeV. Our results suggest that the uncertainties in the extracted B→X_{s}γ rate have been underestimated by up to a factor of 2, leaving more room for beyond-SM contributions.
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