I. Bediaga
A5068644667- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Particle Detector Development and Performance
- Computational Physics and Python Applications
- Black Holes and Theoretical Physics
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Superconducting Materials and Applications
- Medical Imaging Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Stochastic processes and statistical mechanics
- Distributed and Parallel Computing Systems
- Cosmology and Gravitation Theories
- Particle accelerators and beam dynamics
- International Science and Diplomacy
- Cold Atom Physics and Bose-Einstein Condensates
- Nuclear Physics and Applications
- Markov Chains and Monte Carlo Methods
- Radioactive Decay and Measurement Techniques
- Gamma-ray bursts and supernovae
- Physics of Superconductivity and Magnetism
Centro Brasileiro de Pesquisas Físicas
2016-2025
Brazilian Center for Research in Energy and Materials
2025
Centre National de la Recherche Scientifique
2021
Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2021
Institut National de Physique Nucléaire et de Physique des Particules
2021
Université Paris-Saclay
2021
Central China Normal University
2014-2020
University of Chinese Academy of Sciences
2020
Tsinghua University
2020
Peking University
2020
The LHCb experiment is dedicated to precision measurements of CP violation and rare decays B hadrons at the Large Hadron Collider (LHC) CERN (Geneva). initial configuration expected performance detector associated systems, as established by test beam simulation studies, described.
The LHCb detector is a forward spectrometer at the Large Hadron Collider (LHC) CERN. experiment designed for precision measurements of CP violation and rare decays beauty charm hadrons. In this paper performance various sub-detectors trigger system are described, using data taken from 2010 to 2012. It shown that design criteria have been met. excellent has allowed collaboration publish wide range physics results, demonstrating LHCb's unique role, both as heavy flavour general purpose in region.
A narrow pentaquark state, P_{c}(4312)^{+}, decaying to J/ψp, is discovered with a statistical significance of 7.3σ in data sample Λ_{b}^{0}→J/ψpK^{-} decays, which an order magnitude larger than that previously analyzed by the LHCb Collaboration. The P_{c}(4450)^{+} structure formerly reported confirmed and observed consist two overlapping peaks, P_{c}(4440)^{+} P_{c}(4457)^{+}, where this two-peak interpretation 5.4σ. proximity Σ_{c}^{+}D[over ¯]^{0} ¯]^{*0} thresholds peaks suggests they...
An angular analysis of the B 0 → K *0(→ + π −)μ μ − decay is presented. The dataset corresponds to an integrated luminosity 3.0 fb−1 pp collision data collected at LHCb experiment. complete information from used determine CP-averaged observables and CP asymmetries, taking account possible contamination decays with system in S-wave configuration. their correlations are reported bins q 2, invariant mass squared dimuon system. determined both unbinned maximum likelihood fit by using principal...
A test of lepton universality, performed by measuring the ratio branching fractions $B^{0} \rightarrow K^{*0}\mu^{+}\mu^{-}$ and K^{*0}e^{+}e^{-}$ decays, $R_{K^{*0}}$, is presented. The $K^{*0}$ meson reconstructed in final state $K^{+}\pi^{-}$, which required to have an invariant mass within 100$\mathrm{\,MeV}c^2$ known $K^{*}(892)^{0}$ mass. analysis using proton-proton collision data, corresponding integrated luminosity about 3$\mathrm{\,fb}^{-1}$, collected LHCb experiment at...
Abstract The standard model of particle physics currently provides our best description fundamental particles and their interactions. theory predicts that the different charged leptons, electron, muon tau, have identical electroweak interaction strengths. Previous measurements shown a wide range decays are consistent with this principle lepton universality. This article presents evidence for breaking universality in beauty-quark decays, significance 3.1 deviations, based on proton–proton...
Using proton-proton collision data at centre-of-mass energies of $\sqrt{s} = 7$, $8$ and $13\mathrm{\,TeV}$ recorded by the LHCb experiment Large Hadron Collider, corresponding to an integrated luminosity $9\mathrm{\,fb}^{-1}$, invariant mass spectrum $J/ψ$ pairs is studied. A narrow structure around $6.9\mathrm{\,GeV/}c^2$ matching lineshape a resonance broad just above twice are observed. The deviation from nonresonant $J/ψ$-pair production five standard deviations in region between $6.2$...
The ratio of branching fractions ${\cal{R}}(D^{*-})\equiv {\cal{B}}(B^0 \to D^{*-} τ^+ ν_τ)/{\cal{B}}(B^0 μ^+ν_μ)$ is measured using a data sample proton-proton collisions collected with the LHCb detector at center-of-mass energies 7 and 8 TeV, corresponding to an integrated luminosity 3$~$fb$^{-1}$. $τ$ lepton reconstructed three charged pions in final state. A novel method used that exploits different vertex topologies signal backgrounds isolate samples semitauonic decays $b$ hadrons high...
The LHCb Upgrade II will fully exploit the flavour-physics opportunities of HL-LHC, and study additional physics topics that take advantage forward acceptance spectrometer. I begin operation in 2020. Consolidation occur, modest enhancements detector be installed, Long Shutdown 3 LHC (2025) these are discussed here. main installed long shutdown 4 (2030) build on strengths current experiment I. It operate at a luminosity up to $ 2 \times 10^{34} \rm cm^{-2}s^{-1}$, ten times detector. New...
During 2011 the LHCb experiment at CERN collected 1.0 fb−1 of $\sqrt{s} = 7\mbox{~TeV}$ pp collisions. Due to large heavy quark production cross-sections, these data provide unprecedented samples flavoured hadrons. The first results from have made a significant impact on flavour physics landscape and definitively proved concept dedicated in forward region hadron collider. This document discusses implications measurements classes extensions Standard Model, bearing mind interplay with searches...
An angular analysis and a measurement of the differential branching fraction decay B 0 → ϕμ + μ − are presented, using data corresponding to an integrated luminosity 3.0 fb−1 pp collisions recorded by LHCb experiment at $$ \sqrt{s}=7 8 TeV. Measurements reported as function q 2, square dimuon invariant mass results found be consistent with Standard Model. In range 1 < 2 6 GeV2 /c 4, where precise theoretical calculations available, is more than 3σ below Model predictions.
First evidence of a structure in the J/ψΛ invariant mass distribution is obtained from an amplitude analysis Ξb-→J/ψΛK- decays. The observed consistent with being due to charmonium pentaquark strangeness significance 3.1σ including systematic uncertainties and look-elsewhere effect. Its width are determined be 4458.8±2.9-1.1+4.7MeV 17.3±6.5-5.7+8.0MeV, respectively, where quoted statistical systematic. also two resonances. In addition, narrow excited Ξ- states, Ξ1690- Ξ1820-, seen for first...
We present an angular analysis of the $B^{+}\rightarrow K^{\ast+}(\rightarrow K_{S}^{0}\pi^{+})\mu^{+}\mu^{-}$ decay using 9$\,\mbox{fb}^{-1}$ $pp$ collision data collected with LHCb experiment. For first time, full set CP-averaged observables is measured in intervals dimuon invariant mass squared. Local deviations from Standard Model predictions are observed, similar to those previous analyses isospin-partner $B^{0}\rightarrow K^{\ast0}\mu^{+}\mu^{-}$ decay. The global tension dependent on...
The branching fraction of the rare B_{s}^{0}→ϕμ^{+}μ^{-} decay is measured using data collected by LHCb experiment at center-of-mass energies 7, 8, and 13 TeV, corresponding to integrated luminosities 1, 2, 6 fb^{-1}, respectively. reported in intervals q^{2}, square dimuon invariant mass. In q^{2} region between 1.1 6.0 GeV^{2}/c^{4}, measurement found lie 3.6 standard deviations below a model prediction based on combination light cone sum rule lattice QCD calculations. addition, first...
Branching fraction and effective lifetime measurements of the rare decay $B^0_s\to\mu^+\mu^-$ searches for decays $B^0\to\mu^+\mu^-$ $B^0_s\to\mu^+\mu^-\gamma$ are reported using proton-proton collision data collected with LHCb detector at centre-of-mass energies $7$ TeV, $8$ TeV $13$ corresponding to a luminosity $9$ fb$^{-1}$. The branching ${\mathcal{B}}(B^0_s\to\mu^+\mu^-)=\left(3.09^{+0.46+0.15}_{-0.43-0.11}\right)\times 10^{-9}$ $\tau(B^0_s\to\mu^+\mu^-)=(2.07\pm 0.29\pm 0.03)$...
The first simultaneous test of muon-electron universality using B^{+}→K^{+}ℓ^{+}ℓ^{-} and B^{0}→K^{*0}ℓ^{+}ℓ^{-} decays is performed, in two ranges the dilepton invariant-mass squared, q^{2}. analysis uses beauty mesons produced proton-proton collisions collected with LHCb detector between 2011 2018, corresponding to an integrated luminosity 9 fb^{-1}. Each four lepton measurements reported either given q^{2} interval or supersedes previous measurements. results are compatible predictions...
An amplitude analysis of B^{-}→J/ψΛp[over ¯] decays is performed using 4400 signal candidates selected on a data sample pp collisions recorded at center-of-mass energies 7, 8, and 13 TeV with the LHCb detector, corresponding to an integrated luminosity 9 fb^{-1}. A narrow resonance in J/ψΛ system, consistent pentaquark candidate strangeness, observed high significance. The mass width this new state are measured be 4338.2±0.7±0.4 MeV 7.0±1.2±1.3 MeV, where first uncertainty statistical second...
A simultaneous analysis of the B+→K+ℓ+ℓ− and B0→K*0ℓ+ℓ− decays is performed to test muon-electron universality in two ranges square dilepton invariant mass, q2. The measurement uses a sample beauty meson produced proton-proton collisions collected with LHCb detector between 2011 2018, corresponding an integrated luminosity 9 fb−1. sequence multivariate selections strict particle identification requirements produce higher signal purity better statistical sensitivity per unit than previous...
A combined amplitude analysis is performed for the decays B^{0}→D[over ¯]^{0}D_{s}^{+}π^{-} and B^{+}→D^{-}D_{s}^{+}π^{+}, which are related by isospin symmetry. The based on data collected LHCb detector in proton-proton collisions at center-of-mass energies of 7, 8, 13 TeV. full sample corresponds to an integrated luminosity 9 fb^{-1}. Two new resonant states with masses 2.908±0.011±0.020 GeV widths 0.136±0.023±0.013 observed, decay D_{s}^{+}π^{+} D_{s}^{+}π^{-} respectively. former state...
The branching fraction $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}{\ensuremath{\tau}}^{+}{\ensuremath{\nu}}_{\ensuremath{\tau}})$ is measured relative to that of the normalization mode ${B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ using hadronic...
The ratios of branching fractions $\mathcal{R}({D}^{*})\ensuremath{\equiv}\mathcal{B}(\overline{B}\ensuremath{\rightarrow}{D}^{*}{\ensuremath{\tau}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\tau}})/\mathcal{B}(\overline{B}\ensuremath{\rightarrow}{D}^{*}{\ensuremath{\mu}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}})$ and...
We study the Dalitz plot of decay D(+)-->K(-)pi(+)pi(+) with a sample 15090 events from Fermilab experiment E791. Modeling amplitude as coherent sum known Kpi resonances and uniform nonresonant term, we do not obtain an acceptable fit. If allow mass width K(*)(0)(1430) to float, values consistent those PDG but chi(2) per degree freedom fit is still unsatisfactory. A good found when for presence additional scalar resonance, 797+/-19+/-43 MeV/c(2) 410+/-43+/-87 MeV/c(2). The become...