Measurement of lepton universality parameters in $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ and $B^0\to K^{\ast 0}{\ell }^{+}{\ell }^{-}$ decays

Abstract

A simultaneous analysis of the $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ and $B^0\to K^{\ast 0}{\ell }^{+}{\ell }^{-}$ decays is performed to test muon-electron universality in two ranges of the square of the dilepton invariant mass, $q^2$. The measurement uses a sample of beauty meson decays produced in proton-proton collisions collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of $9$ ${\text{fb}}^{-1}$. A sequence of multivariate selections and strict particle identification requirements produce a higher signal purity and a better statistical sensitivity per unit luminosity than previous LHCb lepton universality tests using the same decay modes. Residual backgrounds due to misidentified hadronic decays are studied using data and included in the fit model. Each of the four lepton universality measurements reported is either the first in the given $q^2$ interval or supersedes previous LHCb measurements. The results are compatible with the predictions of the Standard Model.

arXiv commentAll figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-045.html (LHCb public pages)

References in corpus (78)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• A Brief Introduction to PYTHIA 8.1
• Weak Decays Beyond Leading Logarithms
• Observation of $J/\psi p$ resonances consistent with pentaquark states in ${\Lambda }_b^0\to J/\psi K^{-}p$ decays
• Precision Electroweak Measurements on the Z Resonance
• LHCb Detector Performance
• Test of lepton universality using $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• sPlot: a statistical tool to unfold data distributions
• Electroweak Measurements in Electron-Positron Collisions at W-Boson-Pair Energies at LEP
• Test of lepton universality with $B^0\to K^{\ast 0}{\ell }^{+}{\ell }^{-}$ decays
• The LHCb Trigger and its Performance in 2011
• B_{d,s}->rho, omega, K*, phi Decay Form Factors from Light-Cone Sum Rules Revisited
• Performance of the LHCb RICH detector at the LHC
• $B\to V{\ell }^{+}{\ell }^{-}$ in the Standard Model from Light-Cone Sum Rules
• Angular analysis of the $B^0\to K^{\ast 0}{\mu }^{+}{\mu }^{-}$ decay using $3\,\mbox{fb}^{-1}$ of integrated luminosity
• More Model-Independent Analysis of b->s Processes
• On the Standard Model predictions for $R_K$ and $R_{K^{\ast }}$
• Decay Chain Fitting with a Kalman Filter
• Explaining $h\to {\mu }^{\pm }{\tau }^{\mp }$, $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ and $B\to K{\mu }^{+}{\mu }^{-}/B\to K{e}^{+}{e}^{-}$ in a two-Higgs-doublet model with gauged $L_{\mu }-L_{\tau }$
• Observation of the resonant character of the $Z(4430{)}^{-}$ state
• Dressing L_mu - L_tau in Color
• Performance of the LHCb Vertex Locator
• Test of lepton universality in beauty-quark decays
• Differential branching fractions and isospin asymmetries of $B\to K^{(\ast )}{\mu }^{+}{\mu }^{-}$ decays
• Angular Distributions of B -> K ll Decays
• Efficient, reliable and fast high-level triggering using a bonsai boosted decision tree
• Angular analysis and differential branching fraction of the decay $B_s^0\to \varphi {\mu }^{+}{\mu }^{-}$
• $R_K$ and future $b\to s\ell \ell$ BSM opportunities
• Measurement of $CP$-averaged observables in the $B^0\to K^{\ast 0}{\mu }^{+}{\mu }^{-}$ decay
• Performance of the LHCb Outer Tracker
• Performance of the LHCb muon system
• Measurement of the track reconstruction efficiency at LHCb
• Precision measurement and interpretation of inclusive $W^{+}$, $W^{-}$ and $Z/{\gamma }^{\ast }$ production cross sections with the ATLAS detector
• Measurement of b hadron production fractions in 7 TeV pp collisions
• $B\to P$ and $B\to V$ Form Factors from $B$-Meson Light-Cone Sum Rules beyond Leading Twist
• B-decay Anomalies in a Composite Leptoquark Model
• Mass distributions marginalized over per-event errors
• Hint of Lepton Flavour Non-Universality in $B$ Meson Decays
• Differential branching fraction and angular analysis of the decay $B^0\to K^{\ast 0}{\mu }^{+}{\mu }^{-}$
• Selection and processing of calibration samples to measure the particle identification performance of the LHCb experiment in Run 2
• Family non-universal Z' models with protected flavor-changing interactions
• Lepton Flavor Non-Universality in B-meson Decays from a U(2) Flavor Model
• Improved performance of the LHCb Outer Tracker in LHC Run 2
• Reassessing the discovery potential of the $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$ decays in the large-recoil region: SM challenges and BSM opportunities
• Measurements of prompt charm production cross-sections in $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$
• Angular analysis of $B_d^0\to K^{\ast }{\mu }^{+}{\mu }^{-}$ decays in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
• Angular analysis of the decay B0 to K*0 mu mu from pp collisions at sqrt(s) = 8 TeV
• Measurement of angular parameters from the decay ${\mathrm{B}}^0\to {\mathrm{K}}^{\ast 0}{\mu }^{+}{\mu }^{-}$ in proton-proton collisions at $\sqrt{s}=$ 8 TeV
• Branching fraction measurements of the rare $B_s^0\to \varphi {\mu }^{+}{\mu }^{-}$ and $B_s^0\to f_2^{\prime }(1525){\mu }^{+}{\mu }^{-}$ decays
• Status of the $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ anomaly after Moriond 2017
• Test of lepton universality in $b\to s{\ell }^{+}{\ell }^{-}$ decays
• Measurement of b-hadron fractions in 13 TeV pp collisions
• Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Angular analysis of the $B^{+}\to K^{\ast +}{\mu }^{+}{\mu }^{-}$ decay
• Study of the production of ${\Lambda }_b^0$ and ${\overline{B}}^0$ hadrons in $pp$ collisions and first measurement of the ${\Lambda }_b^0\to J/\psi p{K}^{-}$ branching fraction
• LHCb Topological Trigger Reoptimization
• Two-body B Meson Decays to eta and eta': Observation of B->eta K*
• QED Corrections in $\bar{B}\to \bar{K}{\ell }^{+}{\ell }^{-}$ at the Double-Differential Level
• Tests of lepton universality using $B^0\to K_S^0{\ell }^{+}{\ell }^{-}$ and $B^{+}\to K^{\ast +}{\ell }^{+}{\ell }^{-}$ decays
• Hadronic uncertainties in $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$: a state-of-the-art analysis
• Reweighting with Boosted Decision Trees
• W and Z Boson Production in PbarP Collisions at Sqrt(s)=1.8 TeV
• Test of lepton universality with ${\Lambda }_b^0\to p{K}^{-}{\ell }^{+}{\ell }^{-}$ decays
• EOS -- A Software for Flavor Physics Phenomenology
• Observation of the Dalitz Decay ${\eta }^{\prime }\to \gamma e^{+}{e}^{-}$
• Measuring the Breaking of Lepton Flavour Universality in $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$
• Measurement of forward $W\to e\nu$ production in $pp$ collisions at $\sqrt{s}=8$TeV
• QED in $\bar{B}\to \bar{K}{\ell }^{+}{\ell }^{-}$ LFU ratios: Theory versus Experiment, a Monte Carlo Study
• Search for new phenomena in $pp$ collisions in final states with tau leptons, $b$-jets, and missing transverse momentum with the ATLAS detector
• Precision Measurements of $\mathcal{B}[\psi (3686)\to {\pi }^{+}{\pi }^{-}J/\psi ]$ and $\mathcal{B}[J/\psi \to l^{+}{l}^{-}]$
• A Measurement of the W to tau+nu Production Cross Section in p-pbar Collisions at sqrt(s) = 1.8 TeV
• Rate difference between b $\to$ s mu^+ mu^- and b $\to$ s e^+e^- in SUSY with large tan$\beta$
• Measurement of the electron reconstruction efficiency at LHCb
• Measurement of $Z\to {\tau }^{+}{\tau }^{-}$ production in proton-proton collisions at $\sqrt{s}=8$ TeV
• Avoiding biases in binned fits
• Reproducible Experiment Platform
• Lepton universality violation from neutral pion decays in $R_{K^{(\ast )}}$ measurements

Cited by in corpus (34)

• Test of lepton universality in $b\to s{\ell }^{+}{\ell }^{-}$ decays
• Test of lepton flavor universality in B${}^{\pm }$ $\to$ K${}^{\pm }{\mu }^{+}{\mu }^{-}$ and B${}^{\pm }$ $\to$ K${}^{\pm }$e${}^{+}$e${}^{-}$ decays in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Review of Semileptonic $B$ Anomalies
• Constraining rare B decays by ${\mu }^{+}{\mu }^{-}\to tc$ at future lepton colliders
• Diquark Explanation of $b\to s{\ell }^{+}{\ell }^{-}$
• Search for a ${\tau }^{+}{\tau }^{-}$ resonance in $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}{\tau }^{+}{\tau }^{-}$ events with the Belle II experiment
• Test of lepton flavour universality with $B_s^0\to \varphi {\ell }^{+}{\ell }^{-}$ decays
• Measurement of the ${\Lambda }_b^0\to \Lambda (1520){\mu }^{+}{\mu }^{-}$ differential branching fraction
• Flavor physics in SU(5) GUT with scalar fields in the 45 representation
• Physical-mass calculation of $\rho (770)$ and $K^{\ast }(892)$ resonance parameters via $\pi \pi$ and $K\pi$ scattering amplitudes from lattice QCD
• Search for a new $Z^{\prime }$ gauge boson via the $pp\to W^{\pm (\ast )}\to Z^{\prime }{\mu }^{\pm }\nu \to {\mu }^{\pm }{\mu }^{\mp }{\mu }^{\pm }\nu$ process in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Data-driven analyses and model-independent fits for present $b\to s\ell \ell$ results
• Neutrinophilic DM annihilation in a model with $U(1{)}_{L_{\mu }-L_{\tau }}\times U(1{)}_H$ gauge symmetry
• Exploring New Physics in transition $b\to s{\ell }^{+}{\ell }^{-}$ through different $B_c\to D_s^{(\ast )}{\ell }^{+}{\ell }^{-}$ observables
• Maximising the physics potential of $B^{\pm }\to {\pi }^{\pm }{\mu }^{+}{\mu }^{-}$ decays
• Scrutinizing $B^0$-meson flavor changing neutral current decay into scalar $K_0^{\ast }(1430)$ meson with $b\to s{\ell }^{+}{\ell }^{-}(\nu \bar{\nu })$ transition
• Semi-visible dark photon in a model with vector-like leptons for the $(g-2{)}_{e,\mu }$ and $W$-boson mass anomalies
• Flavor phenomenology of an extended 2HDM with inverse seesaw mechanism
• Test of lepton flavour universality with $B^{+}\to K^{+}{\pi }^{+}{\pi }^{-}{\ell }^{+}{\ell }^{-}$ decays
• A gauged non-universal $U(1{)}_X$ model to study muon $g-2$ and $B$ meson anomalies
• Fundamental Physics in 2025: Status, Decisive Targets, and Path Forward
• Three decades of FCNC studies in 3-3-1 model with right-handed neutrinos: from $Z^{\prime }$-dominance to the alignment limit
• Precision Tests in $b\to s{\ell }^{+}{\ell }^{-}$ ($\ell =e,\mu$) at FCC-ee
• Decay $B_c^{+}\to D_{(s)}^{(\ast )+}{\ell }^{+}{\ell }^{-}$ within covariant confined quark model
• Addressing the $R_{\tau /\mu ,e}\left(D^{(\ast )}\right)$ puzzle through New Physics four-fermion operators and their impact on ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ decay
• Constraints on new physics from decays of polarized ${\Lambda }_b^0$ baryons at the FCC-ee
• Semileptonic neutral current decays of ${\Xi }_b$ with dileptons or dineutrinos in the final state
• ${\Xi }_b\to \Xi$ form factors from lattice QCD and Standard-Model predictions for ${\Xi }_b\to \Xi {\mu }^{+}{\mu }^{-}$ and ${\Xi }_b\to \Xi \gamma$ decays
• Flavour Physics at LHCb -- 50 years of the KM paradigm
• The Angular Observables of ${\Lambda }_b\to {\Lambda }_c(\to {\Lambda }^0{\pi }^{+}){\tau }^{-}(\to {\pi }^{-}{\nu }_{\tau }){\bar{\nu }}_{\tau }$ within the Paradigm of FCCC Anomalies
• Probing mixed-state dark matter and flavor observables in a scalar-assisted baryonic gauge theory
• Polarized and un-polarized ${\mathcal{R}}_{K^{\ast }}$ in and beyond the SM
• $B_{(s)}\to S(a_0(1450),K_0^{\ast }(1430),f_0(1500))$ helicity form factors within QCD light-cone sum rules
• Non-parametric and continuous extraction of amplitudes in electroweak penguin decays