A5048500933- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Computational Physics and Python Applications
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Black Holes and Theoretical Physics
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Stochastic processes and statistical mechanics
- Medical Imaging Techniques and Applications
- Superconducting Materials and Applications
- Geophysics and Gravity Measurements
- Markov Chains and Monte Carlo Methods
- Advanced Data Storage Technologies
- Radiation Detection and Scintillator Technologies
- Cosmology and Gravitation Theories
- International Science and Diplomacy
- GNSS positioning and interference
- Radio Astronomy Observations and Technology
- Radioactive Decay and Measurement Techniques
- Astrophysics and Cosmic Phenomena
- Microstructure and Mechanical Properties of Steels
Istituto Nazionale di Fisica Nucleare, Sezione di Genova
2023-2025
Peking University
2023-2024
State Key Laboratory of Nuclear Physics and Technology
2023-2024
University of Chinese Academy of Sciences
2023-2024
Lomonosov Moscow State University
2019-2023
European Organization for Nuclear Research
2022-2023
Universitat de Barcelona
2023
Jönköping University
2022
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...
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...
A bstract The W boson mass is measured using proton-proton collision data at $$ \sqrt{s} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt></mml:math> = 13 TeV corresponding to an integrated luminosity of 1.7 fb − 1 recorded during 2016 by the LHCb experiment. With a simultaneous fit muon q/p T distribution sample → μν decays and ϕ * Z μμ determined be {m}_w=80354\pm {23}_{\mathrm{stat}}\pm {10}_{\mathrm{exp}}\pm {17}_{\mathrm{theory}}\pm...
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...
Tests of lepton universality in B^{0}→K_{S}^{0}ℓ^{+}ℓ^{-} and B^{+}→K^{*+}ℓ^{+}ℓ^{-} decays where ℓ is either an electron or a muon are presented. The differential branching fractions B^{0}→K_{S}^{0}e^{+}e^{-} B^{+}→K^{*+}e^{+}e^{-} measured intervals the dilepton invariant mass squared. measurements performed using proton-proton collision data recorded by LHCb experiment, corresponding to integrated luminosity 9 fb^{-1} . results consistent with standard model previous tests related decay...
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 bstract We develop the formalism for production of a fully heavy tetraquark and apply it to calculation pp → T 4 c + X cross-sections. demonstrate that cross-section tetraquark, even if is diquark-antidiquark cluster, can be obtained in meson-like basis, which spin-color projection technique well established. Prompted by recent LHCb, ATLAS CMS data, we perform pQCD $$ \mathcal{O} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>O</mml:mi> </mml:math> ( {\alpha}_s^5...
The ratio of the B0s and B0 fragmentation fractions, fs/fd, in proton-proton collisions at LHC, is obtained as a function B-meson transverse momentum collision center-of-mass energy from combined analysis different B-decay channels measured by LHCb experiment. results are described linear meson or with inspired Tsallis statistics. Precise measurements branching fractions B0s→J/ψϕ B0s→D−sπ+ decays performed, reducing their uncertainty about factor 2 respect to previous world averages....
Resonant contributions in $B^0 \rightarrow \overline{D}^0 D^+_s\pi^-$ and $B^+\rightarrow D^- D^+_s\pi^+$ decays are determined with an amplitude analysis, which is performed both separately simultaneously, where the latter case isospin symmetry between assumed. The analysis based on data collected by LHCb detector proton-proton collisions at center-of-mass energies of 7, 8 13 $\rm{TeV}$. full sample corresponds to integrated luminosity 9 $\rm fb^{-1}$. A doubly charged spin-0 open-charm...
A bstract The cross-sections of exclusive (coherent) photoproduction J/ψ and ψ (2S) mesons in ultra-peripheral PbPb collisions at a nucleon-nucleon centre-of-mass energy 5 . 02 TeV are measured using data sample corresponding to an integrated luminosity 228 ± 10 μb − 1 , collected by the LHCb experiment 2018. differential separately as function transverse momentum rapidity nucleus-nucleus frame for mesons. be $$ {\sigma}_{J/\psi}^{\textrm{coh}} <mml:math...
A measurement of time-dependent <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>C</a:mi><a:mi>P</a:mi></a:math> violation in the decays <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msup><c:mi>B</c:mi><c:mn>0</c:mn></c:msup></c:math> and <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msup><e:mover accent="true"><e:mi>B</e:mi><e:mo stretchy="false">¯</e:mo></e:mover><e:mn>0</e:mn></e:msup></e:math> mesons to...
Abstract The LHCb upgrade represents a major change of the experiment. detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that previous periods. Readout all into all-software trigger is central new design, facilitating reconstruction events maximum LHC interaction rate, and their selection in real time. experiment's tracking system has upgraded with pixel vertex detector, silicon tracker upstream dipole magnet three...
The production rate of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msubsup><a:mi mathvariant="normal">Λ</a:mi><a:mi>b</a:mi><a:mn>0</a:mn></a:msubsup></a:math> baryons relative to <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:msup><d:mi>B</d:mi><d:mn>0</d:mn></d:msup></d:math> mesons in <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"><f:mi>p</f:mi><f:mi>p</f:mi></f:math> collisions at a center-of-mass energy...
A measurement of the time-dependent ratio <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>D</a:mi><a:mn>0</a:mn></a:msup><a:mo stretchy="false">→</a:mo><a:mrow><a:msup><a:mi>K</a:mi><a:mo>+</a:mo></a:msup><a:msup><a:mi>π</a:mi><a:mo>−</a:mo></a:msup></a:mrow></a:math> to <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:mrow><d:mrow><d:msup><d:mrow><d:mover accent="true"><d:mrow><d:mi>D</d:mi></d:mrow><d:mrow><d:mo...
Abstract Charged-particle trajectories are usually reconstructed with the LHCb detector using combined information from tracking devices placed upstream and downstream of 4 T m dipole magnet. Trajectories only tracker magnet, which referred to as tracks, have not been used for physics analysis date. The challenges reconstruction long-lived particles tracks use discussed solutions proposed. feasibility performance studied samples $$\varvec{\Lambda }$$ <mml:math...
The first study of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>J</a:mi><a:mo>/</a:mo><a:mi>ψ</a:mi><a:mi>ϕ</a:mi></a:math> production in diffractive processes proton-proton collisions is presented. based on an LHCb dataset recorded at center-of-mass energy 13 TeV, corresponding to integrated luminosity <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mn>5</c:mn><c:mtext> </c:mtext><c:mtext>...
An angular analysis of the rare decay $B^0_s\rightarrow\phi\mu^+\mu^-$ is presented, using proton-proton collision data collected by LHCb experiment at centre-of-mass energies $7$, $8$ and $13~\rm{TeV}$, corresponding to an integrated luminosity $8.4~\rm{fb}^{-1}$. The observables describing distributions are determined in regions $q^2$, square dimuon invariant mass. results consistent with Standard Model predictions.