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arXiv · 1408.4097

Hint of Lepton Flavour Non-Universality in $B$ Meson Decays

Diptimoy Ghosh·Marco Nardecchia·S. A. Renner
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Abstract

The LHCb collaboration has recently presented their result on R_K = BR(B+ -> K+ mu+ mu-)/ BR(B+ -> K+ e+ e-) for the dilepton invariant mass bin m_{ll}^2 = 1-6 GeV^2 (l = mu, e). The measurement shows an intriguing 2.6 sigma deviation from the Standard Model (SM) prediction. In view of this, we study model independent New Physics (NP) explanations of R_K consistent with other measurements involving b -> s l l transition, relaxing the assumption of lepton universality. We perform a Bayesian statistical fit to the NP Wilson Coefficients and compare the Bayes Factors of the different hypotheses in order to quantify their goodness-of-fit. We show that the data slightly favours NP in the muon sector over NP in the electron sector.

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Diptimoy Ghosh, Marco Nardecchia, S. A. Renner. 2014-12-02. Hint of Lepton Flavour Non-Universality in $B$ Meson Decays. https://doi.org/10.1007/jhep12(2014)131

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