A5063750433- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Black Holes and Theoretical Physics
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Superconducting Materials and Applications
- Stochastic processes and statistical mechanics
- Cosmology and Gravitation Theories
- Distributed and Parallel Computing Systems
- Astrophysics and Cosmic Phenomena
- Advanced NMR Techniques and Applications
- International Science and Diplomacy
- Markov Chains and Monte Carlo Methods
- Radioactive Decay and Measurement Techniques
- Muon and positron interactions and applications
- CCD and CMOS Imaging Sensors
- Cold Atom Physics and Bose-Einstein Condensates
École Polytechnique Fédérale de Lausanne
2016-2025
Kolding Hospital
2024
European Organization for Nuclear Research
1990-2024
Keldysh Institute of Applied Mathematics
2023
Universitat de Barcelona
2023
Kurchatov Institute
2022
Centro Brasileiro de Pesquisas Físicas
2013-2017
High Energy Accelerator Research Organization
2014
Danish Gas Technology Centre (Denmark)
2013
University of Zurich
2013
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...
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 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...
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...
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...
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 $6.2$...
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...
The $\Xi_c^+ K^-$ mass spectrum is studied with a sample of $pp$ collision data corresponding to an integrated luminosity 3.3 fb$^{-1}$, collected by the LHCb experiment. $\Xi_c^+$ reconstructed in decay mode $p K^- \pi^+$. Five new, narrow excited $\Omega_c^0$ states are observed: $\Omega_c(3000)^0$, $\Omega_c(3050)^0$, $\Omega_c(3066)^0$, $\Omega_c(3090)^0$, and $\Omega_c(3119)^0$. Measurements their masses widths reported.
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...
A search for charge-parity (CP) violation in D^{0}→K^{-}K^{+} and D^{0}→π^{-}π^{+} decays is reported, using pp collision data corresponding to an integrated luminosity of 5.9 fb^{-1} collected at a center-of-mass energy 13 TeV with the LHCb detector. The flavor charm meson inferred from charge pion D^{*}(2010)^{+}→D^{0}π^{+} or muon B[over ¯]→D^{0}μ^{-}ν[over ¯]_{μ}X decays. difference between CP asymmetries measured be ΔA_{CP}=[-18.2±3.2(stat)±0.9(syst)]×10^{-4} π-tagged...
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 full amplitude analysis of $B^+\to J/ψϕK^+$ with $J/ψ\toμ^+μ^-$, $ϕ\to K^+K^-$ decays is performed a data sample 3 fb$^{-1}$ $pp$ collision collected at $\sqrt{s}=7$ and $8$ TeV the LHCb detector. cannot be described by model that contains only excited kaon states decaying into $ϕK^+$, four $J/ψϕ$ structures are observed, each significance over $5$ standard deviations. quantum numbers these determined least $4$ lightest has mass consistent with, but width much larger than, previous...
Searches are performed for both prompt-like and long-lived dark photons, $A^{\prime}$, produced in proton-proton collisions at a center-of-mass energy of 13 TeV, using $A^{\prime}\to\mu^+\mu^-$ decays data sample corresponding to an integrated luminosity 1.6 fb$^{-1}$ collected with the LHCb detector. The $A^{\prime}$ search covers mass range from near dimuon threshold up 70 GeV, while is restricted low-mass region $214<m(A^{\prime})<350$ MeV. No evidence signal found, 90% confidence level...