B 781, 517541 (2018). Energy Phys. The Standard Model predicts that this occurs via electroweak bosons and the W + and Z 0 particles. 118, 111801 (2017). High Energy Phys. Rev. Beauty quarks test lepton universality - CERN Courier Flavour physics Feature Beauty quarks test lepton universality 23 March 2018 A series of measurements from LHCb and B-factory experiments have tested whether the interactions of charged leptons agree with the Standard Model. The BDT output is not strongly correlated with q2, and the same classifiers are used to select the respective resonant decays. J. C 78, 451 (2018). The effect on RK is at the 1% level. Rev. Alguer, M. et al. Simulated events are used to derive the two ratios of efficiencies needed to form RK using equation (2). Khodjamirian, A., Mannel, T., Pivovarov, A. This estimate takes into account the spectrum of the relevant variables in the non-resonant decay modes of interest and is compatible with the estimated systematic uncertainties on RK. The LHCb simulation application, Gauss: design, evolution and experience. Phys. In the electron minimum pT spectra, the structure at 2800 MeV/c is related to the trigger threshold. Correlations in the systematic uncertainties between different trigger categories and run periods are taken into account. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF, DFG and MPG (Germany); INFN (Italy); NWO (Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MSHE (Russia); MICINN (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); DOE NP and NSF (United States). Eur. For the electron modes that dictate the RK precision, this requirement reduces the combinatorial background by approximately 99% while retaining 85% of the signal mode. Rev. Rev. Geng, L.-S. et al. Test of lepton universality in beauty-quark decays (Journal Article J. High. This can be interpreted as a world-leading test of lepton flavour universality in (2S)+ decays. The relative fraction of partially reconstructed background in each trigger category is also shared across the different data-taking periods. These ratios have been determined to be 2.12.5 standard deviations below their respective SM expectations3,4,5,6,7,16,17,18,19,20,21,22. {6\ }_{-\ 1.4}^{+\ 1.5}\ \pm 1.3)\times 1{0}^{-9}\ {c}^{4}\,{{{{\rm{GeV}}}}}^{-2}\ .\end{array}$$, \(\overline{b}\to \overline{s}{\ell }^{+}{\ell }^{-}\), \(\overline{b}\to \overline{s}{\tau }^{+}{\tau }^{-}\), \(B\to {H}_{c}(\to {K}^{+}{\ell }^{-}{\overline{\nu }}_{\ell }X){\ell }^{+}{\nu }_{\ell }Y\), $$\begin{array}{rcl}{R}_{K}&=&\frac{N({B}^{+}\to {K}^{+}{\mu }^{+}{\mu }^{-})}{\varepsilon ({B}^{+}\to {K}^{+}{\mu }^{+}{\mu }^{-})}\cdot \frac{\varepsilon ({B}^{+}\to {K}^{+}{e}^{+}{e}^{-})}{N({B}^{+}\to {K}^{+}{e}^{+}{e}^{-})}\\ &&\times \frac{\varepsilon ({B}^{+}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){K}^{+})}{N({B}^{+}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){K}^{+})}\cdot \frac{N({B}^{+}\to J/\psi (\to {e}^{+}{e}^{-}){K}^{+})}{\varepsilon ({B}^{+}\to J/\psi (\to {e}^{+}{e}^{-}){K}^{+})}\ ,\end{array}$$, \(\overline{B}\to \overline{K}{{{{\rm{\ell }}}}}^{+}{{{{\rm{\ell }}}}}^{-}\), \({\Lambda }_{b}^{0}\to p{K}^{-}{\ell }^{+}{\ell }^{-}\), \({B}_{d}^{0}\to {K}^{* }{\mu }^{+}{\mu }^{-}\), \({B}_{s}^{0}\to \phi {\mu }^{+}{\mu }^{-}\), \({\Lambda }_{b}^{0}\to \Lambda {\mu }^{+}{\mu }^{-}\), \({B}_{s}^{0}\to \ \ \phi {\mu }^{+}{\mu }^{-}\), \(\overline{B}\to \ \ {D}^{(*)}{\tau }^{-}{\overline{\nu }}_{\tau }\), \({{{\mathcal{B}}}}({B}_{c}^{+}\to J/\psi {\tau }^{+}{\nu }_{\tau })/{{{\mathcal{B}}}}{{{\mathcal{B}}}}({B}_{c}^{+}\to J/\psi {\mu }^{+}{\nu }_{\mu })\), \({\overline{B}}^{0}\to {D}^{* +}{\tau }^{-}{\overline{\nu }}_{\tau }\), \({\overline{B}}^{0}\to {D}^{* +}{\ell }^{-}{\overline{\nu }}_{\ell }\), \({{{\mathcal{B}}}}({\overline{B}}^{0}\to {D}^{* +}{\tau }^{-}{\overline{\nu }}_{\tau })/{{{\mathcal{B}}}}({\overline{B}}^{0}\to {D}^{* +}{\mu }^{-}{\overline{\nu }}_{\mu })\), \({B}^{0}\to \ \ {D}^{(*)}{\tau }^{-}{\overline{\nu }}_{\tau }\), \(\overline{B}\to \ \ {D}^{(*)}{\ell }^{-}{\overline{\nu }}_{\ell }\), \(\overline{B}\to {D}^{* }{\tau }^{-}{\overline{\nu }}_{\tau }\), \({{{\mathcal{B}}}}[\psi (3686)\to \ \ {\pi }^{+}{\pi }^{-}J/\psi ]\), \({{{\mathcal{B}}}}[J/\psi \to \ \ {\ell }^{+}{\ell }^{-}]\), \({B}_{s}^{0}\to {\tau }^{+}{\tau }^{-}\), https://doi.org/10.1038/s41567-021-01478-8. This article presents evidence for the breaking of lepton universality in beauty-quark decays, with a significance of 3.1 standard deviations, based on proton-proton collision data collected with the LHCb detector at CERN's Large Hadron Collider. The Belle collaboration et al. In the fits to non-resonant B+K+e+e candidates, the mass shape of the background from B+J/(e+e)K+ decays with an emitted photon that is not reconstructed is also taken from simulation and, adjusting for the relevant selection efficiency, its yield is constrained to the value from the fit to the resonant mode within its uncertainty. Phys. Candidate B+K++ decays are found by combining the reconstructed trajectory (track) of a particle identified as a charged kaon, together with the tracks from a pair of well-reconstructed oppositely charged particles identified as either electrons or muons. In addition to the process discussed above, the K++ final state is produced via a \({B}^{+}\to {X}_{q\overline{q}}{K}^{+}\) decay, where \({X}_{q\overline{q}}\) is a bound state (meson) such as the J/. An uncertainty comparable to that from the modelling of the signal and background components is induced by the limited sizes of calibration samples. Lepton avour universality tests in electroweak penguin decays at LHCbSebastian Schmitt 1. Phys. (Bottom) the single ratio rJ/ relative to its average value \(< {r}_{J/\psi } >\) as a function of these variables. Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands, R. Aaij,J. S. Butter,K. Carvalho Akiba,S. Ferreres Sole,E. Gabriel,R. E. Geertsema,L. M. Greeven,K. Heijhoff,W. Hulsbergen,D. Hynds,E. Jans,S. Klaver,P. Koppenburg,I. Kostiuk,H. S. Kuindersma,M. Lucio Martinez,V. Lukashenko,A. Mauri,M. Merk,A. Pellegrino,C. Sanchez Gras,M. Schubiger,A. Snoch,N. Tuning,A. Usachov,M. van Beuzekom&M. Veronesi, Physik-Institut, Universitt Zrich, Zrich, Switzerland, C. Abelln Beteta,M. Atzeni,R. Bernet,C. Betancourt,Ia. High. Even though the non-resonant and resonant samples are mutually exclusive as a function of q2, there is significant overlap between them in the quantities on which the efficiency depends, such as the laboratory-frame momenta of the final-state particles or the opening angle between the two leptons. Other explanations of the data involve a variety of extensions to the SM, such as supersymmetry, extended Higgsboson sectors and models with extra dimensions. Phys. Aebischer, J. et al. reco. 115, 111803 (2015); erratum 115, 159901 (2015). Observables studied include rare meson decays, flavor oscillations of neutral mesons, rare lepton decays, and dipole moments. The majority of the sources of systematic uncertainty affect the relative efficiencies between non-resonant and resonant decays. This article presents evidence for the breaking of lepton universality in beauty-quark decays, with a significance of 3.1 standard deviations, based on protonproton collision data collected with the LHCb detector at CERNs Large Hadron Collider. 3). https://doi.org/10.1038/s41567-021-01478-8, DOI: https://doi.org/10.1038/s41567-021-01478-8. Each top (antitop) quark decays almost immediately into a bottom b ( b) quark and a W+ ( W -) boson, and we have reexamined those events in which one of the W bosons decays into a charged. Update of lepton universality test measurement RK - CERN Test of lepton flavor universality by the measurement of the B0D*+ branching fraction using three-prong decays. The Large Hadron Collider beauty collaboration reports a test of lepton flavour universality in decays of bottom mesons into strange mesons and a charged lepton pair, finding evidence of a violation of this principle postulated in the standard model. (Top) distributions of the reconstructed spectra of (left) the angle between the leptons, (+,), and (right) the minimum pT of the leptons for B+K++ and B+J/(+)K+ decays. Hint of lepton flavour non-universality in B meson decays. The rJ/ ratio is therefore also computed as a function of different kinematic variables. Measurements from Run 1 of decays of beauty hadrons at the LHCb experiment, in addition to earlier results from the B-facto - Beauty quarks test lepton universality A series of measurements from LHCb and B-factory experiments have tested whether the interactions of charged leptons agree with the Standard Model. Left: the SM contribution involves the electroweak bosons ,W+ and Z0, and the up-type quarks , \(\bar{c}\) and \(\bar{t}\). J. Phys. High. D 69, 074020 (2004). These are included in the fit to RK by allowing the relative efficiency to vary within Gaussian constraints. Extended Data Table 1 Nonresonant and resonant mode. Rev. The fit projection is superimposed, with dotted lines describing the signal contribution and solid areas representing each of the background components described in the text and listed in the legend. To take into account residual differences in the signal shape between data and simulation, an offset in the peak position and a scaling of the resolution are allowed to vary in the fits to the resonant modes. Belyaev, I. et al. & Wang, Y.-M. Charm-loop effect in B K(*)+ and B K*. J. Test of lepton universality in beauty-quark decays Standard Model of particle physics currently predicts that the different charged leptons, the electron, muon and tau, have identical electroweak interaction strengths. 109, 101802 (2012). The Belle II physics book. Lett. Lees, J. P. et al. High Energy Phys. Predictions for lepton flavor universality violation in rare B decays in models with gauged LL. Aaij, R. et al. Article 2019, 89 (2019). (Right) the bin definition in this two-dimensional space together with the distribution for B+K+e+e (B+J/(e+e)K+) decays depicted as red (blue) contours. The top row shows the fit to the muon modes and the subsequent rows the fits to the electron modes triggered by (second row) one of the electrons, (third row) the kaon and (last row) by other particles in the event. A comparable uncertainty arises from the limited size of the calibration samples, with negligible contributions from the calibration of the B+ production kinematics and modelling of the selection and particle-identification efficiencies. The classifier includes the following variables: the pT of the B+, K+ and dilepton candidates, and the minimum and maximum pT of the leptons; the B+, dilepton and K+\({\chi }_{{{{\rm{IP}}}}}^{2}\) with respect to the associated PV, where \({\chi }_{{{{\rm{IP}}}}}^{2}\) is defined as the difference in the vertex-fit 2 of the PV reconstructed with and without the considered particle; the minimum and maximum \({\chi }_{{{{\rm{IP}}}}}^{2}\) of the leptons; the B+ vertex-fit quality; the statistical significance of the B+ flight distance; and the angle between the B+ candidate momentum vector and the direction between the associated PV and the B+ decay vertex. Such a modification can be realized in new physics models with an additional heavy neutral boson or with leptoquarks. Phys. Phys. Nucl. B. Zonneveld, Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania, L. Cojocariu,A. Ene,L. Giubega,A. Grecu,F. Maciuc,V. Placinta&M. Straticiuc, L. Congedo,M. De Serio,R. A. Fini,A. Palano,M. Pappagallo,A. Pastore&S. Simone, L. Congedo,M. De Serio,M. Pappagallo&S. Simone, Los Alamos National Laboratory (LANL), Los Alamos, NM, USA, J. Crkovsk,C. L. Da Silva,C. T. Dean,J. M. Durham,E. Epple&G. J. Kunde, Van Swinderen Institute, University of Groningen, Groningen, Netherlands, K. De Bruyn,C. J. G. Onderwater&M. van Veghel, Universiteit Maastricht, Maastricht, Netherlands, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakw, Poland, A. Dendek,M. Firlej,T. Fiutowski,M. Idzik,P. Kopciewicz,W. Krupa,O. Madejczyk,M. W. Majewski,J. Moron,A. Oblakowska-Mucha,B. Rachwal,J. Ryzka,K. Swientek&T. Szumlak, F. Dettori,C. Giugliano,G. Manca,R. Oldeman&B. Saitta, Eotvos Lorand University, Budapest, Hungary, Institute for Nuclear Research of the National Academy of Sciences (KINR), Kyiv, Ukraine, V. Dobishuk,S. Koliiev,I. Kostiuk,O. Kot&V. Pugatch, School of Physics, University College Dublin, Dublin, Ireland, A. M. Donohoe,L. Mcconnell,R. McNulty,N. V. Raab&C. B. High. Huschle, M. et al. The electron and muon veto cuts differ given the relative helicity suppression of ++ decays. In the muon case, K[] combinations with mass smaller than \(m_{D^0}\) are rejected. LHCb collaboration, Test of lepton universality in beauty-quark decays, Nature Phys. Geant4 developments and applications, IEEE Trans. Rev. The theory predicts that the different charged leptons, the electron, muon and tau, have identical electroweak interaction. Pseudo-experiments are also used to assess the degree of bias originating from the fitting procedure. The extent of the dark, medium and light blue regions shows the values allowed for RK at 1, 3 and 5 levels. The raw data in all of the figures of this paper, and additional supplementary material, can be downloaded from https://cds.cern.ch/record/2758740, where no access codes are required. Uncertainties on the data points are statistical only and represent one standard deviation, calculated assuming Poisson-distributed entries. Phys. The bias is found to be 1% of the statistical precision and thus negligible with respect to other sources of systematic uncertainty. J. Phys. Sjstrand, T., Mrenna, S. & Skands, P. PYTHIA 6.4 physics and manual. Whenever B+J/(+)K+ events are used to correct the simulation, the correlations between calibration and measurement samples are taken into account in the results and cross-checks presented in this paper. These two processes are separated by applying a requirement on q2. D 97, 072013 (2018). Ghosh, D., Nardecchia, M. & Renner, S. A. Yields of the nonresonant and resonant decay modes obtained from the fits to the data. The expected values from simulated events are used to constrain the fraction of signal decays in each of these categories. LHCb collaboration et al. High. The fit projections are superimposed, with dotted lines describing the signal contribution and solid areas representing each of the background components described in the text and listed in the legend. Lett. Test of lepton universality in beauty-quark decays, arXiv:2103.1176 . On Drell-Yan production of scalar leptoquarks coupling to heavy-quark J. Phys. Rev. 4 Likelihood function from the fit to the nonresonant. The corresponding parameters are then fixed in the fits to the relevant non-resonant modes. 120, 121801 (2018). High Energy Phys. However, a bremsstrahlung photon emitted upstream of the magnet will deposit energy in a different part of the ECAL than the electron, which is deflected in the magnetic field. Ser. In addition, rJ/ is computed in two-dimensional intervals of reconstructed quantities (Extended Data Fig. Nature Physics thanks Akimasa Ishikawa, Marcella Bona and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. The large interaction strengths preclude predictions of QCD effects with the perturbation techniques used to compute the electroweak force amplitudes, and only approximate calculations are currently possible. Clemencic, M. et al. Fan,J. Nucl. The resonant yields are determined from separate fits to mJ/(K++). Test of Lepton Flavour Universality using a measurement of R(D*) with If confirmed by future measurements, this violation of lepton universality would imply physics beyond the standard model, such as a new fundamental interaction between quarks and leptons. Scienze Fisiche e Naturali (2023), Nature Physics (Nat. C 82, 7 (2022). 04, 016 (2017). The B+K+e+e branching fraction is determined by combining the value of RK with the value of \({{{\rm{d}}}}{{{\mathcal{B}}}}\ ({B}^{+}\to {K}^{+}{\mu }^{+}{\mu }^{-})/{{{\rm{d}}}}{q}^{2}\) in the region 1.1
test of lepton universality in beauty quark decays naturehillcrest memorial park obituaries
B 781, 517541 (2018). Energy Phys. The Standard Model predicts that this occurs via electroweak bosons and the W + and Z 0 particles. 118, 111801 (2017). High Energy Phys. Rev. Beauty quarks test lepton universality - CERN Courier Flavour physics Feature Beauty quarks test lepton universality 23 March 2018 A series of measurements from LHCb and B-factory experiments have tested whether the interactions of charged leptons agree with the Standard Model. The BDT output is not strongly correlated with q2, and the same classifiers are used to select the respective resonant decays. J. C 78, 451 (2018). The effect on RK is at the 1% level. Rev. Alguer, M. et al. Simulated events are used to derive the two ratios of efficiencies needed to form RK using equation (2). Khodjamirian, A., Mannel, T., Pivovarov, A. This estimate takes into account the spectrum of the relevant variables in the non-resonant decay modes of interest and is compatible with the estimated systematic uncertainties on RK. The LHCb simulation application, Gauss: design, evolution and experience. Phys. In the electron minimum pT spectra, the structure at 2800 MeV/c is related to the trigger threshold. Correlations in the systematic uncertainties between different trigger categories and run periods are taken into account. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF, DFG and MPG (Germany); INFN (Italy); NWO (Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MSHE (Russia); MICINN (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); DOE NP and NSF (United States). Eur. For the electron modes that dictate the RK precision, this requirement reduces the combinatorial background by approximately 99% while retaining 85% of the signal mode. Rev. Rev. Geng, L.-S. et al. Test of lepton universality in beauty-quark decays (Journal Article J. High. This can be interpreted as a world-leading test of lepton flavour universality in (2S)+ decays. The relative fraction of partially reconstructed background in each trigger category is also shared across the different data-taking periods. These ratios have been determined to be 2.12.5 standard deviations below their respective SM expectations3,4,5,6,7,16,17,18,19,20,21,22. {6\ }_{-\ 1.4}^{+\ 1.5}\ \pm 1.3)\times 1{0}^{-9}\ {c}^{4}\,{{{{\rm{GeV}}}}}^{-2}\ .\end{array}$$, \(\overline{b}\to \overline{s}{\ell }^{+}{\ell }^{-}\), \(\overline{b}\to \overline{s}{\tau }^{+}{\tau }^{-}\), \(B\to {H}_{c}(\to {K}^{+}{\ell }^{-}{\overline{\nu }}_{\ell }X){\ell }^{+}{\nu }_{\ell }Y\), $$\begin{array}{rcl}{R}_{K}&=&\frac{N({B}^{+}\to {K}^{+}{\mu }^{+}{\mu }^{-})}{\varepsilon ({B}^{+}\to {K}^{+}{\mu }^{+}{\mu }^{-})}\cdot \frac{\varepsilon ({B}^{+}\to {K}^{+}{e}^{+}{e}^{-})}{N({B}^{+}\to {K}^{+}{e}^{+}{e}^{-})}\\ &&\times \frac{\varepsilon ({B}^{+}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){K}^{+})}{N({B}^{+}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){K}^{+})}\cdot \frac{N({B}^{+}\to J/\psi (\to {e}^{+}{e}^{-}){K}^{+})}{\varepsilon ({B}^{+}\to J/\psi (\to {e}^{+}{e}^{-}){K}^{+})}\ ,\end{array}$$, \(\overline{B}\to \overline{K}{{{{\rm{\ell }}}}}^{+}{{{{\rm{\ell }}}}}^{-}\), \({\Lambda }_{b}^{0}\to p{K}^{-}{\ell }^{+}{\ell }^{-}\), \({B}_{d}^{0}\to {K}^{* }{\mu }^{+}{\mu }^{-}\), \({B}_{s}^{0}\to \phi {\mu }^{+}{\mu }^{-}\), \({\Lambda }_{b}^{0}\to \Lambda {\mu }^{+}{\mu }^{-}\), \({B}_{s}^{0}\to \ \ \phi {\mu }^{+}{\mu }^{-}\), \(\overline{B}\to \ \ {D}^{(*)}{\tau }^{-}{\overline{\nu }}_{\tau }\), \({{{\mathcal{B}}}}({B}_{c}^{+}\to J/\psi {\tau }^{+}{\nu }_{\tau })/{{{\mathcal{B}}}}{{{\mathcal{B}}}}({B}_{c}^{+}\to J/\psi {\mu }^{+}{\nu }_{\mu })\), \({\overline{B}}^{0}\to {D}^{* +}{\tau }^{-}{\overline{\nu }}_{\tau }\), \({\overline{B}}^{0}\to {D}^{* +}{\ell }^{-}{\overline{\nu }}_{\ell }\), \({{{\mathcal{B}}}}({\overline{B}}^{0}\to {D}^{* +}{\tau }^{-}{\overline{\nu }}_{\tau })/{{{\mathcal{B}}}}({\overline{B}}^{0}\to {D}^{* +}{\mu }^{-}{\overline{\nu }}_{\mu })\), \({B}^{0}\to \ \ {D}^{(*)}{\tau }^{-}{\overline{\nu }}_{\tau }\), \(\overline{B}\to \ \ {D}^{(*)}{\ell }^{-}{\overline{\nu }}_{\ell }\), \(\overline{B}\to {D}^{* }{\tau }^{-}{\overline{\nu }}_{\tau }\), \({{{\mathcal{B}}}}[\psi (3686)\to \ \ {\pi }^{+}{\pi }^{-}J/\psi ]\), \({{{\mathcal{B}}}}[J/\psi \to \ \ {\ell }^{+}{\ell }^{-}]\), \({B}_{s}^{0}\to {\tau }^{+}{\tau }^{-}\), https://doi.org/10.1038/s41567-021-01478-8. This article presents evidence for the breaking of lepton universality in beauty-quark decays, with a significance of 3.1 standard deviations, based on proton-proton collision data collected with the LHCb detector at CERN's Large Hadron Collider. The Belle collaboration et al. In the fits to non-resonant B+K+e+e candidates, the mass shape of the background from B+J/(e+e)K+ decays with an emitted photon that is not reconstructed is also taken from simulation and, adjusting for the relevant selection efficiency, its yield is constrained to the value from the fit to the resonant mode within its uncertainty. Phys. Candidate B+K++ decays are found by combining the reconstructed trajectory (track) of a particle identified as a charged kaon, together with the tracks from a pair of well-reconstructed oppositely charged particles identified as either electrons or muons. In addition to the process discussed above, the K++ final state is produced via a \({B}^{+}\to {X}_{q\overline{q}}{K}^{+}\) decay, where \({X}_{q\overline{q}}\) is a bound state (meson) such as the J/. An uncertainty comparable to that from the modelling of the signal and background components is induced by the limited sizes of calibration samples. Lepton avour universality tests in electroweak penguin decays at LHCbSebastian Schmitt 1. Phys. (Bottom) the single ratio rJ/ relative to its average value \(< {r}_{J/\psi } >\) as a function of these variables. Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands, R. Aaij,J. S. Butter,K. Carvalho Akiba,S. Ferreres Sole,E. Gabriel,R. E. Geertsema,L. M. Greeven,K. Heijhoff,W. Hulsbergen,D. Hynds,E. Jans,S. Klaver,P. Koppenburg,I. Kostiuk,H. S. Kuindersma,M. Lucio Martinez,V. Lukashenko,A. Mauri,M. Merk,A. Pellegrino,C. Sanchez Gras,M. Schubiger,A. Snoch,N. Tuning,A. Usachov,M. van Beuzekom&M. Veronesi, Physik-Institut, Universitt Zrich, Zrich, Switzerland, C. Abelln Beteta,M. Atzeni,R. Bernet,C. Betancourt,Ia. High. Even though the non-resonant and resonant samples are mutually exclusive as a function of q2, there is significant overlap between them in the quantities on which the efficiency depends, such as the laboratory-frame momenta of the final-state particles or the opening angle between the two leptons. Other explanations of the data involve a variety of extensions to the SM, such as supersymmetry, extended Higgsboson sectors and models with extra dimensions. Phys. Aebischer, J. et al. reco. 115, 111803 (2015); erratum 115, 159901 (2015). Observables studied include rare meson decays, flavor oscillations of neutral mesons, rare lepton decays, and dipole moments. The majority of the sources of systematic uncertainty affect the relative efficiencies between non-resonant and resonant decays. This article presents evidence for the breaking of lepton universality in beauty-quark decays, with a significance of 3.1 standard deviations, based on protonproton collision data collected with the LHCb detector at CERNs Large Hadron Collider. 3). https://doi.org/10.1038/s41567-021-01478-8, DOI: https://doi.org/10.1038/s41567-021-01478-8. Each top (antitop) quark decays almost immediately into a bottom b ( b) quark and a W+ ( W -) boson, and we have reexamined those events in which one of the W bosons decays into a charged. Update of lepton universality test measurement RK - CERN Test of lepton flavor universality by the measurement of the B0D*+ branching fraction using three-prong decays. The Large Hadron Collider beauty collaboration reports a test of lepton flavour universality in decays of bottom mesons into strange mesons and a charged lepton pair, finding evidence of a violation of this principle postulated in the standard model. (Top) distributions of the reconstructed spectra of (left) the angle between the leptons, (+,), and (right) the minimum pT of the leptons for B+K++ and B+J/(+)K+ decays. Hint of lepton flavour non-universality in B meson decays. The rJ/ ratio is therefore also computed as a function of different kinematic variables. Measurements from Run 1 of decays of beauty hadrons at the LHCb experiment, in addition to earlier results from the B-facto - Beauty quarks test lepton universality A series of measurements from LHCb and B-factory experiments have tested whether the interactions of charged leptons agree with the Standard Model. Left: the SM contribution involves the electroweak bosons ,W+ and Z0, and the up-type quarks , \(\bar{c}\) and \(\bar{t}\). J. Phys. High. D 69, 074020 (2004). These are included in the fit to RK by allowing the relative efficiency to vary within Gaussian constraints. Extended Data Table 1 Nonresonant and resonant mode. Rev. The fit projection is superimposed, with dotted lines describing the signal contribution and solid areas representing each of the background components described in the text and listed in the legend. To take into account residual differences in the signal shape between data and simulation, an offset in the peak position and a scaling of the resolution are allowed to vary in the fits to the resonant modes. Belyaev, I. et al. & Wang, Y.-M. Charm-loop effect in B K(*)+ and B K*. J. Test of lepton universality in beauty-quark decays Standard Model of particle physics currently predicts that the different charged leptons, the electron, muon and tau, have identical electroweak interaction strengths. 109, 101802 (2012). The Belle II physics book. Lett. Lees, J. P. et al. High Energy Phys. Predictions for lepton flavor universality violation in rare B decays in models with gauged LL. Aaij, R. et al. Article 2019, 89 (2019). (Right) the bin definition in this two-dimensional space together with the distribution for B+K+e+e (B+J/(e+e)K+) decays depicted as red (blue) contours. The top row shows the fit to the muon modes and the subsequent rows the fits to the electron modes triggered by (second row) one of the electrons, (third row) the kaon and (last row) by other particles in the event. A comparable uncertainty arises from the limited size of the calibration samples, with negligible contributions from the calibration of the B+ production kinematics and modelling of the selection and particle-identification efficiencies. The classifier includes the following variables: the pT of the B+, K+ and dilepton candidates, and the minimum and maximum pT of the leptons; the B+, dilepton and K+\({\chi }_{{{{\rm{IP}}}}}^{2}\) with respect to the associated PV, where \({\chi }_{{{{\rm{IP}}}}}^{2}\) is defined as the difference in the vertex-fit 2 of the PV reconstructed with and without the considered particle; the minimum and maximum \({\chi }_{{{{\rm{IP}}}}}^{2}\) of the leptons; the B+ vertex-fit quality; the statistical significance of the B+ flight distance; and the angle between the B+ candidate momentum vector and the direction between the associated PV and the B+ decay vertex. Such a modification can be realized in new physics models with an additional heavy neutral boson or with leptoquarks. Phys. Phys. Nucl. B. Zonneveld, Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania, L. Cojocariu,A. Ene,L. Giubega,A. Grecu,F. Maciuc,V. Placinta&M. Straticiuc, L. Congedo,M. De Serio,R. A. Fini,A. Palano,M. Pappagallo,A. Pastore&S. Simone, L. Congedo,M. De Serio,M. Pappagallo&S. Simone, Los Alamos National Laboratory (LANL), Los Alamos, NM, USA, J. Crkovsk,C. L. Da Silva,C. T. Dean,J. M. Durham,E. Epple&G. J. Kunde, Van Swinderen Institute, University of Groningen, Groningen, Netherlands, K. De Bruyn,C. J. G. Onderwater&M. van Veghel, Universiteit Maastricht, Maastricht, Netherlands, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakw, Poland, A. Dendek,M. Firlej,T. Fiutowski,M. Idzik,P. Kopciewicz,W. Krupa,O. Madejczyk,M. W. Majewski,J. Moron,A. Oblakowska-Mucha,B. Rachwal,J. Ryzka,K. Swientek&T. Szumlak, F. Dettori,C. Giugliano,G. Manca,R. Oldeman&B. Saitta, Eotvos Lorand University, Budapest, Hungary, Institute for Nuclear Research of the National Academy of Sciences (KINR), Kyiv, Ukraine, V. Dobishuk,S. Koliiev,I. Kostiuk,O. Kot&V. Pugatch, School of Physics, University College Dublin, Dublin, Ireland, A. M. Donohoe,L. Mcconnell,R. McNulty,N. V. Raab&C. B. High. Huschle, M. et al. The electron and muon veto cuts differ given the relative helicity suppression of ++ decays. In the muon case, K[] combinations with mass smaller than \(m_{D^0}\) are rejected. LHCb collaboration, Test of lepton universality in beauty-quark decays, Nature Phys. Geant4 developments and applications, IEEE Trans. Rev. The theory predicts that the different charged leptons, the electron, muon and tau, have identical electroweak interaction. Pseudo-experiments are also used to assess the degree of bias originating from the fitting procedure. The extent of the dark, medium and light blue regions shows the values allowed for RK at 1, 3 and 5 levels. The raw data in all of the figures of this paper, and additional supplementary material, can be downloaded from https://cds.cern.ch/record/2758740, where no access codes are required. Uncertainties on the data points are statistical only and represent one standard deviation, calculated assuming Poisson-distributed entries. Phys. The bias is found to be 1% of the statistical precision and thus negligible with respect to other sources of systematic uncertainty. J. Phys. Sjstrand, T., Mrenna, S. & Skands, P. PYTHIA 6.4 physics and manual. Whenever B+J/(+)K+ events are used to correct the simulation, the correlations between calibration and measurement samples are taken into account in the results and cross-checks presented in this paper. These two processes are separated by applying a requirement on q2. D 97, 072013 (2018). Ghosh, D., Nardecchia, M. & Renner, S. A. Yields of the nonresonant and resonant decay modes obtained from the fits to the data. The expected values from simulated events are used to constrain the fraction of signal decays in each of these categories. LHCb collaboration et al. High. The fit projections are superimposed, with dotted lines describing the signal contribution and solid areas representing each of the background components described in the text and listed in the legend. Lett. Test of lepton universality in beauty-quark decays, arXiv:2103.1176 . On Drell-Yan production of scalar leptoquarks coupling to heavy-quark J. Phys. Rev. 4 Likelihood function from the fit to the nonresonant. The corresponding parameters are then fixed in the fits to the relevant non-resonant modes. 120, 121801 (2018). High Energy Phys. However, a bremsstrahlung photon emitted upstream of the magnet will deposit energy in a different part of the ECAL than the electron, which is deflected in the magnetic field. Ser. In addition, rJ/ is computed in two-dimensional intervals of reconstructed quantities (Extended Data Fig. Nature Physics thanks Akimasa Ishikawa, Marcella Bona and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. The large interaction strengths preclude predictions of QCD effects with the perturbation techniques used to compute the electroweak force amplitudes, and only approximate calculations are currently possible. Clemencic, M. et al. Fan,J. Nucl. The resonant yields are determined from separate fits to mJ/(K++). Test of Lepton Flavour Universality using a measurement of R(D*) with If confirmed by future measurements, this violation of lepton universality would imply physics beyond the standard model, such as a new fundamental interaction between quarks and leptons. Scienze Fisiche e Naturali (2023), Nature Physics (Nat. C 82, 7 (2022). 04, 016 (2017). The B+K+e+e branching fraction is determined by combining the value of RK with the value of \({{{\rm{d}}}}{{{\mathcal{B}}}}\ ({B}^{+}\to {K}^{+}{\mu }^{+}{\mu }^{-})/{{{\rm{d}}}}{q}^{2}\) in the region 1.1
