K. Carvalho Akiba
A5106498528- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Particle Detector Development and Performance
- Black Holes and Theoretical Physics
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Stochastic processes and statistical mechanics
- CCD and CMOS Imaging Sensors
- Distributed and Parallel Computing Systems
- Cosmology and Gravitation Theories
- International Science and Diplomacy
- Advanced NMR Techniques and Applications
- Particle accelerators and beam dynamics
- Markov Chains and Monte Carlo Methods
- Radiation Effects in Electronics
- Nuclear Physics and Applications
- Astrophysics and Cosmic Phenomena
National Institute for Subatomic Physics
2011-2025
European Organization for Nuclear Research
2008-2023
Petersburg Nuclear Physics Institute
2011-2021
University of Liverpool
2009-2021
Cracow University of Technology
2021
AGH University of Krakow
2021
University of Oxford
2021
TU Dortmund University
2021
Universidade Federal de São Carlos
2021
Anhanguera (Brazil)
2021
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.
Observations of exotic structures in the J/ψp channel, which we refer to as charmonium-pentaquark states, Λ0b→J/ψK−p decays are presented. The data sample corresponds an integrated luminosity 3 fb−1 acquired with LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis three-body final state reproduces two-body mass angular distributions. To obtain a satisfactory fit seen spectrum, it is necessary include two Breit-Wigner amplitudes that each describe resonant state. significance...
A measurement of the ratio branching fractions $B^{+}\rightarrow K^{+}\mu^{+}\mu^{-}$ and K^{+}e^{+}e^{-}$ decays is presented using proton-proton collision data, corresponding to an integrated luminosity 3.0 fb$^{-1}$, recorded with LHCb experiment at center-of-mass energies 7 8 $\mathrm{\,Te\kern -0.1em V}$. The value for dilepton invariant mass squared range $1<q^{2}<6\mathrm{\,Ge\kern V^2\!/}c^4$ measured be $0.745^{+0.090}_{-0.074}\mathrm{\,(stat)}\,\pm0.036\mathrm{\,(syst)}$. This most...
The branching fraction ratio R(D^{*})≡B(B[over ¯]^{0}→D^{*+}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]^{0}→D^{*+}μ^{-}ν[over ¯]_{μ}) is measured using a sample of proton-proton collision data corresponding to 3.0 fb^{-1} integrated luminosity recorded by the LHCb experiment during 2011 and 2012. tau lepton identified in decay mode τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ}. semitauonic sensitive contributions from non-standard-model particles that preferentially couple third generation fermions, particular,...
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.
We present a measurement of form-factor-independent angular observables in the decay ${B}^{0}\ensuremath{\rightarrow}{K}^{*}(892{)}^{0}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$. The analysis is based on data sample corresponding to an integrated luminosity $1.0\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, collected by LHCb experiment $pp$ collisions at center-of-mass energy 7 TeV. Four are measured six bins dimuon invariant mass squared ${q}^{2}$ range...
A search for the rare decays ${B}_{s}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ and ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ is performed with data collected in 2011 2012 LHCb experiment at Large Hadron Collider. The samples comprise $1.1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of proton-proton collisions $\sqrt{s}=8\text{ }\mathrm{TeV}$ $1.0\text{ $\sqrt{s}=7\text{ }\mathrm{TeV}$. We...
The quantum numbers of the X(3872) meson are determined to be JPC = 1++ based on angular correlations in B+ K+ decays, where pi+pi- J/psi and \mu+\mu-. data correspond 1.0 fb-1 pp collisions collected by LHCb detector. only alternative assignment allowed previous measurements, JPC=2-+, is rejected with a confidence level equivalent more than eight Gaussian standard deviations using likelihood-ratio test full phase space. This result favors exotic explanations state.
The Vertex Locator (VELO) is a silicon microstrip detector that surrounds the proton-proton interaction region in LHCb experiment. performance of during first years its physics operation reviewed. system operated vacuum, uses bi-phase CO2 cooling system, and sensors are moved to 7 mm from LHC beam for data taking. stability these characteristic features described, details material budget given. calibration timing processing algorithms implemented FPGAs described. fully characterised. have...
The production of J/psi mesons in proton-proton collisions at sqrt(s)=7 TeV is studied with the LHCb detector LHC. differential cross-section for prompt measured as a function transverse momentum pT and rapidity y fiducial region 0<pT<14 GeV/c 2.0<y<4.5. fraction from b-hadron decays are also same ranges. analysis based on data sample corresponding to an integrated luminosity 5.2pb-1. cross-sections over 10.52 +/- 0.04 1.40 +1.64/-2.20 mub 1.14 0.01 0.16 decays, where first uncertainty...
A search for the rare decays ${B}_{s}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ and ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ is performed at LHCb experiment. The data analyzed correspond to an integrated luminosity of $1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ $pp$ collisions a center-of-mass energy 7 TeV $2\text{ 8 TeV. An excess signal candidates with respect background expectation seen...
A bstract search for $$ {B}_s^0\to {\overline{D}}^0{f}_0(980) <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi>B</mml:mi><mml:mi>s</mml:mi><mml:mn>0</mml:mn></mml:msubsup><mml:mo>→</mml:mo><mml:msup><mml:mover><mml:mi>D</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mn>0</mml:mn></mml:msup><mml:msub><mml:mi>f</mml:mi><mml:mn>0</mml:mn></mml:msub><mml:mfenced><mml:mn>980</mml:mn></mml:mfenced></mml:math> decays is performed using 3 . 0 fb 1− of pp collision data...
Charm production at the LHC in pp collisions s=7TeV is studied with LHCb detector. The decays D0→K−π+, D+→K−π+π+, D⁎+→D0(K−π+)π+, Ds+→ϕ(K−K+)π+, Λc+→pK−π+, and their charge conjugates are analysed a data set corresponding to an integrated luminosity of 15 nb−1. Differential cross-sections dσ/dpT measured for prompt five charmed hadron species bins transverse momentum rapidity region 0<pT<8GeV/c 2.0<y<4.5. Theoretical predictions compared differential cross-sections. charm hadrons computed...
An angular analysis and a measurement of the differential branching fraction decay B 0 → ϕμ + μ − are presented, using data corresponding to an integrated luminosity 3.0 fb−1 pp collisions recorded by LHCb experiment at $$ \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.
The isospin asymmetries of $B \to K\mu^+\mu^-$ and K^{*}\mu^+\mu^-$ decays the partial branching fractions $B^0 K^0\mu^+\mu^-$, $B^+ K^+\mu^+\mu^-$ K^{*+}\mu^+\mu^-$ are measured as functions dimuon mass squared, $q^2$. data used correspond to an integrated luminosity 3$~$fb$^{-1}$ from proton-proton collisions collected with LHCb detector at centre-of-mass energies 7$\,$TeV 8$\,$TeV in 2011 2012, respectively. both consistent Standard Model expectations. three fractions, while individually...
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...
A search for Bs -> mu+ mu- and B0 decays is performed using 1.0 fb^-1 of pp collision data collected at \sqrt{s}=7 TeV with the LHCb experiment Large Hadron Collider. For both number observed events consistent expectation from background Standard Model signal predictions. Upper limits on branching fractions are determined to be BR(Bs mu-) < 4.5 (3.8) x 10^-9 BR(B0 (0.81) 95% (90%) confidence level.
Abstract Using 34.7 pb −1 of data collected with the LHCb detector, inclusive production X (3872) meson in pp collisions at $\sqrt{s}=7\mbox{~TeV}$ is observed for first time. Candidates are selected (3872)→ J / ψπ + π − decay mode, and used to measure "Equation missing" where σ ( → (3872)+anything) cross section mesons rapidity range 2.5–4.5 transverse momentum 5–20 GeV/ c . In addition masses both ψ (2 S ) mesons, reconstructed final state, measured be $$m_{X(3872)} = 3871.95 \pm0.48 \...
Measurements of $b$ hadron production ratios in proton-proton collisions at a centre-of-mass energy 7 TeV with an integrated luminosity 3 pb$^{-1}$ are presented. We study the strange $B$ meson to light $f_s/(f_u+f_d)$ and $\Lambda_b^0$ baryon $f_{\Lambda_b}/(f_u+f_d)$ as function charmed hadron-muon pair transverse momentum $p_T$ pseudorapidity $\eta$, for between 0 14 GeV $\eta$ 2 5. find that is consistent being independent $p_{\rm T}$ we determine = 0.134$\pm$ 0.004 $^{+0.011}_{-0.010}$,...