A5081102322- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Medical Imaging Techniques and Applications
- Superconducting Materials and Applications
- Nuclear physics research studies
- Stochastic processes and statistical mechanics
- Cosmology and Gravitation Theories
- International Science and Diplomacy
- Distributed and Parallel Computing Systems
- Markov Chains and Monte Carlo Methods
- Cold Atom Physics and Bose-Einstein Condensates
- Radiation Detection and Scintillator Technologies
- Astrophysics and Cosmic Phenomena
- Advanced NMR Techniques and Applications
- Stochastic processes and financial applications
- advanced mathematical theories
- Particle accelerators and beam dynamics
University of Zurich
2021-2025
Universitat Ramon Llull
2023-2024
École Polytechnique Fédérale de Lausanne
2015-2023
Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2023
Institut National de Physique Nucléaire et de Physique des Particules
2023
Centre National de la Recherche Scientifique
2023
RWTH Aachen University
2023
Universitat de Barcelona
2023
Kharkiv Institute of Physics and Technology
2023
Université Paris-Saclay
2023
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...
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,...
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...
A highly significant structure is observed in the $\Lambda_c^+K^-\pi^+\pi^+$ mass spectrum, where $\Lambda_c^+$ baryon reconstructed decay mode $pK^-\pi^+$. The consistent with originating from a weakly decaying particle, identified as doubly charmed $\Xi_{cc}^{++}$. difference between masses of $\Xi_{cc}^{++}$ and states measured to be $1334.94 \pm 0.72 (\mathrm{stat}) 0.27 (\mathrm{syst}~\mathrm{MeV}/c^2$, then determined $3621.40 (\mathrm{syst} 0.14 \, (\Lambda_c^+)~\mathrm{MeV}/c^2$,...
A measurement of the ratio branching fractions decays B^{+}→K^{+}μ^{+}μ^{-} and B^{+}→K^{+}e^{+}e^{-} is presented. The proton-proton collision data used correspond to an integrated luminosity 5.0 fb^{-1} recorded with LHCb experiment at center-of-mass energies 7, 8, 13 TeV. For dilepton mass-squared range 1.1<q^{2}<6.0 GeV^{2}/c^{4} measured be R_{K}=0.846_{-0.054}^{+0.060}_{-0.014}^{+0.016}, where first uncertainty statistical second systematic. This most precise R_{K} date compatible...
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 ratio of branching fractions R(D*−)≡B(B0→D*−τ+ντ)/B(B0→D*−μ+νμ) 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. For first time, R(D*−) determined τ-lepton decays three charged pions in final state. B0→D*−τ+ντ yield normalized that B0→D*−π+π−π+ mode, providing measurement B(B0→D*−τ+ντ)/B(B0→D*−π+π−π+)=1.97±0.13±0.18, where uncertainty statistical second...
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 $\Xi_c^+ K^-$ 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.
Abstract Conventional, hadronic matter consists of baryons and mesons made three quarks a quark–antiquark pair, respectively 1,2 . Here, we report the observation state containing four in Large Hadron Collider beauty experiment. This so-called tetraquark contains two charm quarks, $$\overline{{{{{u}}}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mrow> <mml:mi>u</mml:mi> </mml:mrow> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> $$\overline{{{{{d}}}}}$$...
A search for the rare decays B_{s}^{0}→μ^{+}μ^{-} and B^{0}→μ^{+}μ^{-} is performed at LHCb experiment using data collected in pp collisions corresponding to a total integrated luminosity of 4.4 fb^{-1}. An excess observed with significance 7.8 standard deviations, representing first observation this decay single experiment. The branching fraction measured be B(B_{s}^{0}→μ^{+}μ^{-})=(3.0±0.6_{-0.2}^{+0.3})×10^{-9}, where uncertainty statistical second systematic. measurement effective...
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...
A measurement is reported of the ratio branching fractions R(J/ψ)=B(B_{c}^{+}→J/ψτ^{+}ν_{τ})/B(B_{c}^{+}→J/ψμ^{+}ν_{μ}), where τ^{+} lepton identified in decay mode τ^{+}→μ^{+}ν_{μ}ν[over ¯]_{τ}. This analysis uses a sample proton-proton collision data corresponding to 3.0 fb^{-1} integrated luminosity recorded with LHCb experiment at center-of-mass energies 7 and 8 TeV. signal found for B_{c}^{+}→J/ψτ^{+}ν_{τ} significance 3 standard deviations corrected systematic uncertainty, measured be...
An angular analysis of the $B^{0}\rightarrow K^{*0}(\to K^{+}\pi^{-})\mu^{+}\mu^{-}$ decay is presented using a data set corresponding to an integrated luminosity 4.7 fb$^{-1}$ $pp$ collision collected with LHCb experiment. The full $C\!P$-averaged observables are determined in bins invariant mass squared dimuon system. Contamination from decays $K^{+}\pi^{-}$ system S-wave configuration taken into account. tension seen between previous results and Standard Model predictions persists new...
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...
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.
Quantum chromodynamics, the theory of strong force, describes interactions coloured quarks and gluons formation hadronic matter. Conventional matter consists baryons mesons made three quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported narrow state in D
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 promptlike and long-lived dark photons, A^{'}, produced in proton-proton collisions at a center-of-mass energy of 13 TeV. These searches look A^{'}→μ^{+}μ^{-} decays using data sample corresponding to an integrated luminosity 5.5 fb^{-1} collected with the LHCb detector. Neither search finds evidence signal, 90% confidence-level exclusion limits placed on γ-A^{'} kinetic mixing strength. The A^{'} explores mass region from near dimuon threshold up 70 GeV...
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...
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...
Results are reported from an amplitude analysis of the $B^+\to D^+D^-K^+$ decay. The is carried out using LHCb proton-proton collision data taken at $\sqrt{s}=7,8,$ and $13$ TeV, corresponding to a total integrated luminosity 9 fb$^{-1}$. In order obtain good description data, it found be necessary include new spin-0 spin-1 resonances in $D^-K^+$ channel with masses around 2.9 GeV$/c^2$, charmonium resonance proximity spin-2 $\chi_{c2}(3930)$ state. widths these determined, as relative...