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arXiv · hep-ph/9910220

Photonic penguins at two loops and m_t-dependence of BR[ B -> X_s l^+ l^-]

Christoph Bobeth·Mikolaj Misiak·Joerg Urban
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Abstract

We calculate two-loop matching conditions for all the operators that are relevant to B -> X_s l^+ l^- decay in the Standard Model. In effect, we are able to remove the +_16% uncertainty in the decay spectrum, which was mainly due to the renormalization-scale dependence of the top-quark mass. We find 1.46 * 10^-6 for the branching ratio integrated in the domain 0.05 < m_{l^+l^-}^2/m_b^2 < 0.25, for l= e or mu. There remains around 13% perturbative uncertainty in this quantity, while the non-perturbative effects are expected to be smaller.

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Christoph Bobeth, Mikolaj Misiak, Joerg Urban. 1999-10-04. Photonic penguins at two loops and m_t-dependence of BR[ B -> X_s l^+ l^-]. https://doi.org/10.1016/s0550-3213(00)00007-9

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