Angular analysis and differential branching fraction of the decay \({B}_{s}^{0}\to \phi {\mu }^{+}{\mu }^{-}\). Previous measurements have shown a wide range of particle decays are consistent with this principle of lepton universality. The region to the left of the vertical dashed line is rejected. The standard model of particle physics currently provides our best description of fundamental particles and their interactions. 53, 270278 (2006). The theory predicts that the different charged leptons, the electron, muon and tau, have identical electroweak interaction strengths. In addition to affecting the decay rates, new physics can also alter how the decay products are distributed in phase space. Phys. Allison, J. et al. Hambrock, C., Hiller, G., Schacht, S. & Zwicky, R. BK* form factors from flavor data to QCD and back. Intriguing New Results from CERN Challenge Standard Model of Particle The resonant yields are determined from separate fits to mJ/(K++). D 69, 074020 (2004). 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Analogous background sources with a misidentified particle are reduced by applying a similar veto, but with the lepton mass hypothesis changed to that of a pion (denoted []). Resolution effects similarly motivate the choice of non-resonant q2 regions, with a lower limit that excludes contributions from -meson decays and an upper limit that reduces the tail from B+J/(e+e)K+ decays. Extended Data Fig. The LHCb collaboration et al. Test of lepton universality in beauty-quark decays LHCb collaboration* The standard model of particle physics currently provides our best description of fundamental particles and their interactions. Aaij, R. et al. Article This effect is accounted for using simulation (Extended Data Figs. The pT of the final state particles, the vertex-fit 2 and the significance of the flight distance have the most discriminating power. Marks,D. J. Unverzagt,U. Uwer,C. Wang,L. Witola&A. 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High Energy Phys. At the LHC, proton-proton collisions produce copious numbers of bottom quarks and antiquarks, most of which become B mesons. Uncertainties on the data points are statistical only and represent one standard deviation. Observables studied include rare meson decays, flavor oscillations of neutral mesons, rare lepton decays, and dipole moments. Nat. Instrum. The rJ/ ratio is therefore also computed as a function of different kinematic variables. 2017, 112 (2017). All contributing authors, as listed at the end of the manuscript, have contributed to the publication, being variously involved in the design and construction of the detector, writing software, calibrating sub-systems, operating the detector, acquiring data and analysing the processed data. Article The techniques used to identify the different particles and to form B+ candidates are described in Methods. 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Test of lepton universality in beauty-quark decays, \({q}_{\min }^{2} < {q}^{2} < {q}_{\max }^{2}\), $${R}_{H}\equiv \frac{\int\nolimits_{{q}_{\min }^{2}}^{{q}_{\max }^{2}}\frac{{{{\rm{d}}}}{{{\mathcal{B}}}}\ \ (B\to H{\mu }^{+}{\mu }^{-})}{{{{\rm{d}}}}{q}^{2}}{{{\rm{d}}}}{q}^{2}}{\int\nolimits_{{q}_{\min }^{2}}^{{q}_{\max }^{2}}\frac{{{{\rm{d}}}}{{{\mathcal{B}}}}\ \ (B\to H{e}^{+}{e}^{-})}{{{{\rm{d}}}}{q}^{2}}{{{\rm{d}}}}{q}^{2}}\,.$$, \(\overline{b}\to \overline{s}{\mu }^{+}{\mu }^{-}\), \(\overline{b}\to \overline{c}{\ell }^{+}{\nu }_{\ell }\), \({B}^{+}\to {X}_{q\overline{q}}{K}^{+}\), $${R}_{K}=\frac{{{{\mathcal{B}}}}\ \ ({B}^{+}\to {K}^{+}{\mu }^{+}{\mu }^{-})}{{{{\mathcal{B}}}}\ \ ({B}^{+}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){K}^{+})}/\frac{{{{\mathcal{B}}}}\ \ ({B}^{+}\to {K}^{+}{e}^{+}{e}^{-})}{{{{\mathcal{B}}}}\ \ ({B}^{+}\to J/\psi (\to {e}^{+}{e}^{-}){K}^{+})}\ .$$, $${r}_{J/\psi }={{{\mathcal{B}}}}\ ({B}^{+}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){K}^{+})/{{{\mathcal{B}}}}\ ({B}^{+}\to J/\psi (\to {e}^{+}{e}^{-}){K}^{+}),$$, \({B}^{+}\to {\overline{D}}^{0}(\to {K}^{+}{e}^{-}{\overline{\nu }}_{e}){e}^{+}{\nu }_{e}\), $$\begin{array}{l}{R}_{\psi (2S)}\\=\frac{{{{\mathcal{B}}}}\ ({B}^{+}\to \psi (2S)(\to {\mu }^{+}{\mu }^{-}){K}^{+})}{{{{\mathcal{B}}}}\ ({B}^{+}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){K}^{+})}/\frac{{{{\mathcal{B}}}}\ ({B}^{+}\to \psi (2S)(\to {e}^{+}{e}^{-}){K}^{+})}{{{{\mathcal{B}}}}\ ({B}^{+}\to J/\psi (\to {e}^{+}{e}^{-}){K}^{+})}\ ,\end{array}$$, $${R}_{K}(1.1 < {q}^{2} < 6.0\,{{{{\rm{GeV}}}}}^{2}\,{c}^{-4})=0.84{6}_{-0.039-0.012}^{+0.042+0.013}\ ,$$, \({R}_{K}=0.84{6}_{-\ 0.041}^{+\ 0.044}\), \({B}^{0}\to {K}_{{{{\rm{S}}}}}^{0}{\ell }^{+}{\ell }^{-}\), \({{{\rm{d}}}}{{{\mathcal{B}}}}\ ({B}^{+}\to {K}^{+}{\mu }^{+}{\mu }^{-})/{{{\rm{d}}}}{q}^{2}\), $$\begin{array}{rcl}\frac{{{{\rm{d}}}}{{{\mathcal{B}}}}\ ({B}^{+}\to {K}^{+}{e}^{+}{e}^{-})}{{{{\rm{d}}}}{q}^{2}}(1.1 < {q}^{2} < 6.0\,{{{{\rm{GeV}}}}}^{2}{c}^{-4})\\=(28. 118, 031802 (2017). 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