Abstract
We attempt to explain recent anomalies in semileptonic B decays at LHCb via a composite Higgs model, in which both the Higgs and an SU(2) L -triplet leptoquark arise as pseudo-Goldstone bosons of the strong dynamics. Fermion masses are assumed to be generated via the mechanism of partial compositeness, which largely determines the leptoquark couplings and implies non-universal lepton interactions. The latter are needed to accommodate tensions in the b → sμμ dataset and to be consistent with a discrepancy measured at LHCb in the ratio of B + → K + μ + μ − to B + → K + e + e − branching ratios. The data imply that the leptoquark should have a mass of around a TeV. We find that the model is not in conflict with current flavour or direct production bounds, but we identify a few observables for which the new physics contributions are close to current limits and where the leptoquark is likely to show up in future measurements. The leptoquark will be pair-produced at the LHC and decay predominantly to third-generation quarks and leptons, and LHC13 searches will provide further strong bounds.
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Gripaios, B., Nardecchia, M. & Renner, S.A. Composite leptoquarks and anomalies in B-meson decays. J. High Energ. Phys. 2015, 6 (2015). https://doi.org/10.1007/JHEP05(2015)006
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DOI: https://doi.org/10.1007/JHEP05(2015)006