test of lepton universality in beauty quark decays nature

The signal mass shapes of the electron modes are described with the sum of three distributions, which model whether the ECAL energy deposit from a bremsstrahlung photon was added to both, either or neither of the e candidates. D 69, 074020 (2004). Rev. Test of lepton universality in beauty-quark decays. According to the Standard Model of particle physics, particles such as beauty quarks should decay into either muons or electrons in equal measure. Phys. Rev. Measurements of the angular distributions in the decays BK(*)+ at CDF. 115, 111803 (2015); erratum 115, 159901 (2015). J. Wei J.-T. et al. Measurements of other RH observables with the full LHCb dataset will provide further information on the quark-level processes measured. 2020, 40 (2020). Beaujean, F., Bobeth, C. & van Dyk, D. Comprehensive Bayesian analysis of rare (semi)leptonic and radiative B decays. Test of lepton universality in beauty-quark decays - INSPIRE Phys. Phys. decays of heavy quarks. The distribution of this ratio as a function of the angle between the leptons and the minimum pT of the leptons is shown in Extended Data Fig. Charpentier,G. Ciezarek,M. Clemencic,J. Closier,V. Coco,P. Collins,T. Colombo,G. Corti,B. Couturier,C. DAmbrosio,P. dArgent,H. Dijkstra,L. Dufour,P. Durante,T. Evans,M. Fo,M. Ferro-Luzzi,R. Forty,M. Frank,C. Frei,W. Funk,S. Gambetta,C. Gaspar,C. Giugliano,E. L. Gkougkousis,E. Govorkova,L. A. Granado Cardoso,T. Gys,C. Haen,J. Haimberger,C. Hasse,M. Hatch,A. M. Hennequin,R. Jacobsson,S. Jakobsen,D. Johnson,B. Jost,N. Jurik,M. Karacson,F. Keizer,R. D. Krawczyk,D. Lacarrere,R. Lindner,B. Malecki,C. Marin Benito,L. Martinazzoli,R. Matev,Z. Mathe,M. Mazurek,M. Mikhasenko,M. Milovanovic,D. S. Mitzel,F. Muheim,M. Mulder,D. Mller,P. Muzzetto,N. Neufeld,P. R. Pais,A. Pearce,M. Pepe Altarelli,M. Petric,F. Pisani,S. Ponce,D. Popov,L. Promberger,P. Roloff,T. Ruf,M. Salomoni,H. Schindler,B. Schmidt,A. Schopper,R. Schwemmer,P. Seyfert,F. Stagni,S. Stahl,M. Szymanski,F. Teubert,E. Thomas,N. Tuning,A. Valassi,C. Vzquez Sierra,K. Wyllie&O. Zenaiev, School of Physics and Astronomy, University of Glasgow, Glasgow, UK, M. Alexander,D. Bobulska,G. Coombs,L. Douglas,L. Eklund,D. A. Friday,I. Longstaff,M. Petric,G. Sarpis,M. Schiller,F. J. P. Soler&P. Spradlin, ICCUB, Universitat de Barcelona, Barcelona, Spain, A. Alfonso Albero,A. Camboni,J. M. Fernandez-tenllado Arribas,P. Garcia Moreno,L. Garrido,P. Gironella Gironell,S. Gomez Fernandez,E. Graugs,J. Mauricio&D. Sanchez Gonzalo, Department of Physics and Astronomy, University of Manchester, Manchester, UK, Z. Aliouche,R. J. Barlow,A. Bitadze,S. Borghi,J. L. Cobbledick,A. Davis,O. Phys. The combined statistical and systematic uncertainty is then determined by scanning the profile likelihood, and the statistical contribution to the uncertainty is isolated by repeating the scan with the efficiencies fixed to their fitted values. 3 Resonant candidates invariant mass distributions. Wang, Y. & Wang, Y.-M. Charm-loop effect in B K(*)+ and B K*. J. C 79, 719 (2019). J. C76, 440 (2016). Eur. The measurements are of processes in which a beauty meson transforms into a strange meson with the emission of either an electron and a positron, or a muon and an antimuon. Measurement of the branching ratio of \({B}^{0}\to \ \ {D}^{(*)}{\tau }^{-}{\overline{\nu }}_{\tau }\) relative to \(\overline{B}\to \ \ {D}^{(*)}{\ell }^{-}{\overline{\nu }}_{\ell }\) decays with hadronic tagging at Belle. For the non-resonant candidates, the m(K+e+e)and m(K++)distributions are fitted with a likelihood function that has the B+K++ yield and RK as fit parameters and the resonant decay mode yields incorporated as Gaussian-constraint terms. The LHCb collaboration et al. 2014, 125 (2014). The green and purple components correspond to candidates with \({q}_{{{{\rm{t}}}}rue}^{2} > 6.0\) GeV 2/c4 and \({q}_{{{{\rm{t}}}}rue}^{2} < 1.1\) GeV 2/c4, respectively. On Drell-Yan production of scalar leptoquarks coupling to heavy-quark Rev. Methods A 462, 152155 (2001). 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. The theory predicts that the different charged leptons, the electron, muon and tau . (Left, with log y-scale) the bremsstrahlung correction to the momentum of the electron is applied, resulting in a tail to the right. The k-folding technique is used in the training and testing81. In the electron case, a 40MeV c2 window around the D0 mass is used to reject candidates where the veto is applied without the bremsstrahlung recovery, that is, on the basis of only the measured track momenta. The authors declare no competing interests. These fractions are observed to agree well with those observed in resonant events selected from the data. However, the intervals of the likelihood distribution are found to be the same when estimated with 1/RK as the fit parameter. Lessons from the B0,+K*0,++ angular analyses. Comput. The B+J/(+)K+ decays are not suppressed and hence have a branching fraction orders of magnitude larger than that of B+K++ decays. The veto requirements retain 97% of B+K++ and 95% of B+K+e+e decays passing all other selection requirements. Lett. Pion electronic decay and lepton universality - ResearchGate A weighted least-squares method is then employed to find the precise vertex position. The fits to the non-resonant (resonant) decay modes in different data-taking periods and trigger categories are shown in Extended Data Fig. Altmannshofer, W., Niehoff, C., Stangl, P. & Straub, D. M. Status of the BK*+ anomaly after Moriond 2017. The LHCb simulation application, Gauss: design, evolution and experience. Lett. Beauty quarks don't exist in large numbers in the world around as they are incredibly short-lived surviving on average for just a trillionth of a second before transforming or decaying into other particles. Measurement of CP-averaged observables in the B0K*0+ decay. The simulated data used in this analysis are produced using the software described in refs. Precision measurements of \({{{\mathcal{B}}}}[\psi (3686)\to \ \ {\pi }^{+}{\pi }^{-}J/\psi ]\) and \({{{\mathcal{B}}}}[J/\psi \to \ \ {\ell }^{+}{\ell }^{-}]\). For the RK measurement, candidate events are required to have passed a hardware trigger algorithm that selects either a high-pT muon, or an electron, hadron or photon with high transverse energy deposited in the calorimeters. The weights are calculated by requiring that simulated B+J/(+)K+ events exhibit the same trigger performance as the control data. Martnez Santos, D. & Dupertuis, F. Mass distributions marginalized over per-event errors. 2). Lees, J. P. et al. (Right, with linear y-scale) the mass is computed only from the track information. Since the associated data storage and analysis costs would be prohibitive, the experiment does not record all collisions. D 96 (2017) 095010 [ arXiv:1704.06659] [ INSPIRE ]. J. Phys. Eur. The theory predicts that the different charged leptons, the electron, muon and tau, have . J. Instrum. Phys. The first decay involves the electron and the second the muon, another elementary particle similar to the electron but approximately 200 times heavier. LHCb topological trigger reoptimization. EPJ Web Conf. Such decays are highly suppressed1, and the fraction of B+ hadrons that decay into this final state (the branching fraction, \({{{\mathcal{B}}}}\)) is on the order of 106 (ref. The y-axis in each figure shows the number of candidates in an interval of the indicated width. LHCb explores the beauty of lepton universality | CERN Rev. 5, together with the spectra expected for the resonant and non-resonant decays. Hint of lepton flavour non-universality in B meson decays. Ratio between the likelihood value (L) and that found by the fit (\({L}_{\max }\)) as a function of RK. Pion electronic decay and lepton universality License CC BY 4.0 Authors: Dinko Pocanic Abstract In common with a number of simple processes involving elementary particles, charged pion decays. Particle Data Group et al. 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. J. Nucl. Geant4: a simulation toolkit. The muon BDT classifier has similar performance. The region to the left of the vertical dashed line is rejected. A comparison with previous measurements is shown in Fig. Phys. J. 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. Blum, A., Kalai, A. Eur. High. Measurement of the branching ratio of \({\overline{B}}^{0}\to {D}^{* +}{\tau }^{-}{\overline{\nu }}_{\tau }\) relative to \({\overline{B}}^{0}\to {D}^{* +}{\ell }^{-}{\overline{\nu }}_{\ell }\) decays with a semileptonic tagging method. Measurement of \({{{\mathcal{R}}}}(D)\) and \({{{\mathcal{R}}}}({D}^{* })\) with a semileptonic tagging method. Jan 2019; PHYS REV LETT; which does not benefit from the same cancellation of systematic effects. The theory predicts that the different charged leptons, the electron, muon and tau, have identical electroweak interaction strengths. Theor. The LHCb experiment75,76 is instrumented in the region covering the polar angles between 10 and 250mrad around the proton beam axis, in which the products from B hadron decays can be efficiently captured and identified. 664, 082025 (2015). The theory predicts that the different charged leptons, the electron, muon and tau, have identical electroweak interaction. 108, 081807 (2012). s In addition to the LHCb result, the measurements by the BaBar15 and Belle13 collaborations, which combine B+K++ and \({B}^{0}\to {K}_{{{{\rm{S}}}}}^{0}{\ell }^{+}{\ell }^{-}\) decays, are also shown. High Energy Phys. Uncertainties on the data points are statistical only and represent one standard deviation, calculated assuming Poisson-distributed entries. Caria, G. et al. The analogous ratio has also been measured for \({\Lambda }_{b}^{0}\) decays with H=pK and is compatible with unity at the level of one standard deviation23. The fit is of good quality, and the value of RK is measured to be. Article Test of the universality of and lepton couplings in W-boson decays with the ATLAS detector, A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery, Search for charged-lepton-flavour violation in Z-boson decays with the ATLAS detector, Evidence for intrinsic charm quarks in the proton, Precise determination of the (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. 2016, 65 (2016). Phys. Eur. J. Phys. Other experiments should also be able to determine RH ratios, with the Belle II experiment in particular expected to have competitive sensitivity72. 82,83,84,85,86,87,88. Isidori, G., Nabeebaccus, S. & Zwicky, R. QED corrections in \(\overline{B}\to \overline{K}{{{{\rm{\ell }}}}}^{+}{{{{\rm{\ell }}}}}^{-}\) at the double-differential level. Global analysis of bs anomalies. 118, 111801 (2017). Bremsstrahlung emission in the decay of particles is simulated using the PHotos software in the default configuration89, which is observed to agree with an independent quantum electrodynamics calculation at the level of 1% (ref. 2013, 010 (2013). Belyaev, I. et al. Wills Physics Laboratory, University of Bristol, Bristol, UK, M. Adinolfi,S. Bhasin,P. Camargo Magalhaes,M. G. Chapman,R. Lane,S. Maddrell-Mander,L. R. Madhan Mohan,A. M. Marshall,P. Naik,D. P. OHanlon,K. Petridis,G. J. Pomery,J. H. Rademacker,J. J. Velthuis,R. Wang,B. D. C. Westhenry&M. Whitehead, Universit Clermont Auvergne, CNRS/IN2P3, LPC, Clermont-Ferrand, MI, France, H. Afsharnia,Z. Ajaltouni,E. Cogneras,O. Deschamps,R. Lefvre,J. Maratas,S. Monteil,P. Perret,D. Popov,H. Sazak,L. Soares Lavra&V. Tisserand, C. A. Aidala,D. S. Fitzgerald,S. H. Lee,K. R. Mattioli,C. Nunez,J. D. Roth&D. M. Shangase, S. Aiola,J. Fu,P. Gandini,L. Henry,D. Marangotto,A. Merli,N. Neri,M. Petruzzo&E. Spadaro Norella, University of Cincinnati, Cincinnati, OH, USA, S. Akar,P. Ilten,B. Meadows,C. Pappenheimer,M. D. Sokoloff,M. Stahl&D. Vieira, Fakultt Physik, Technische Universitt Dortmund, Dortmund, Germany, J. Albrecht,A. Battig,M. Becker,M. S. Bieker,J. & Langford J. Preprint at https://arxiv.org/abs/1406.0566 (2014). Hambrock, C., Hiller, G., Schacht, S. & Zwicky, R. BK* form factors from flavor data to QCD and back. A. Boelhauve,L. Calefice,E. DallOcco,H.-P. Dembinski,Q. Fuehring,L. L. Gerken,K. Heinicke,S. E. Hollitt,P. Ibis,V. Jevtic,B. Khanji,J. Langer,V. Lisovskyi,P. Mackowiak,G. Meier,A. Mdden,T. Mombcher,N. S. Nolte,M. Saur,M. Schellenberg,A. Seuthe,B. Spaan,H. Stevens&D. Wiedner, European Organization for Nuclear Research (CERN), Geneva, Switzerland, F. Alessio,L. An,C. Bertella,F. Betti,M. P. Blago,N. Bondar,A. Boyer,M. Brodski,C. Burr,J. Buytaert,W. Byczynski,M. Cattaneo,G. Cavallero,Ph. W. Altmannshofer, P.S. A significant proportion (0.7%) of this uncertainty comes from the limited knowledge of the K spectrum in B(0,+)K+(,0)e+e decays. Phys. Davidson, N., Przedzinski, T. & Was, Z. Lane,A. Lupato,T. H. Mcgrath,A. McNab,B. Mitreska,D. Murray,Y. Pan,C. Parkes,F. Reiss,N. Skidmore,P. Svihra,S. Taneja,D. J. Hiller, G. & Krger, F. More model-independent analysis of bs processes. High. 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. LHCb collaboration. Phys. The residual contribution from such decays is considered as a source of systematic uncertainty. You are using a browser version with limited support for CSS. After the application of the selection requirements, the resonant and non-resonant decays are clearly visible in the mass distributions (Fig. Back,T. Blake,A. Brossa Gonzalo,M. F. Cicala,C. M. Costa Sobral,L. M. Garcia Martin,T. Gershon,R. J. Confirmation of any effect beyond the SM will clearly require independent evidence from a wide range of sources. LHCb collaboration Physics case for an LHCb upgrade IIopportunities in flavour physics, and beyond, in the HL-LHC era. 126, 161801 (2021). 331, 032047 (2011). To avoid unconscious bias, the analysis procedure was developed and the cross-checks described below performed before the result for RK was examined. The dominant such background for the non-resonant and resonant modes comes from partially reconstructed B(0,+)K+(,0)e+e and B(0,+)J/(e+e)K+(,0) decays, respectively, where the pion is not included in the B+ candidate. 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. The 1.1

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