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Three-loop QCD corrections to $B_{s} \rightarrow \mu^{+}\mu^{-}$

The decay B_s -> mu^+ mu^- in the Standard Model is generated by the well-known W-box and Z-penguin diagrams that give rise to an effective quark-lepton operator Q_A at low energies. We compute QCD corrections of order alpha_s^2 to its Wilson coefficient C_A. It requires performing three-loop mat...

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Detalles Bibliográficos
Autores principales: Hermann, Thomas, Misiak, Mikolaj, Steinhauser, Matthias
Lenguaje:eng
Publicado: 2013
Materias:
Acceso en línea:https://dx.doi.org/10.1007/JHEP12(2013)097
http://cds.cern.ch/record/1625764
Descripción
Sumario:The decay B_s -> mu^+ mu^- in the Standard Model is generated by the well-known W-box and Z-penguin diagrams that give rise to an effective quark-lepton operator Q_A at low energies. We compute QCD corrections of order alpha_s^2 to its Wilson coefficient C_A. It requires performing three-loop matching between the full and effective theories. Including the new corrections makes C_A more stable with respect to the matching scale mu_0 at which the top-quark mass and alpha_s are renormalized. The corresponding uncertainty in |C_A|^2 gets reduced from around 1.8% to less than 0.2%. Our results are directly applicable to all the B_{s(d)} -> l^+ l^- decay modes.