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Two-Loop Matrix Element of the Current-Current Operator in the Decay B -> X_s gamma

Andrzej J. Buras·Andrzej Czarnecki·Mikolaj Misiak·Joerg Urban
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Abstract

We evaluate the important two-loop matrix element of the operator (cbar gamma^mu P_L b) (sbar gamma_mu P_L b) contributing to the inclusive radiative decay B -> X_s gamma. The calculation is performed in the NDR scheme, by means of asymptotic expansions method. The result is given as a series in z = m_c^2/m_b^2 up to O(z^6). We confirm the result of Greub, Hurth and Wyler obtained by a different method up to 0(z^3). Higher-order terms are found to be numerically insignificant.

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Andrzej J. Buras, Andrzej Czarnecki, Mikolaj Misiak, Joerg Urban. 2001-05-16. Two-Loop Matrix Element of the Current-Current Operator in the Decay B -> X_s gamma. https://doi.org/10.1016/s0550-3213(01)00336-4

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