E. Bertholet
A5101572655- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Computational Physics and Python Applications
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Black Holes and Theoretical Physics
- Medical Imaging Techniques and Applications
- Nuclear physics research studies
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- International Science and Diplomacy
- advanced mathematical theories
- Stochastic processes and statistical mechanics
- Advanced NMR Techniques and Applications
- Radioactive Decay and Measurement Techniques
- Distributed and Parallel Computing Systems
- Cold Atom Physics and Bose-Einstein Condensates
- Radioactivity and Radon Measurements
- Calibration and Measurement Techniques
- Markov Chains and Monte Carlo Methods
- Cosmology and Gravitation Theories
- Insurance, Mortality, Demography, Risk Management
Tel Aviv University
2021-2023
Laboratoire de Physique Nucléaire et de Hautes Énergies
2017-2021
Sorbonne Paris Cité
2018-2021
Université Paris Cité
2017-2021
Délégation Paris 7
2018-2021
Sorbonne Université
2017-2021
Centre National de la Recherche Scientifique
2017-2021
Peking University
2020
State Key Laboratory of Nuclear Physics and Technology
2020
Central China Normal University
2020
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...
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...
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 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...
This paper reports world averages of measurements $b$-hadron, $c$-hadron, and $\tau$-lepton properties obtained by the Heavy Flavour Averaging Group using results available before April 2021. In rare cases, significant several months later are also used. For averaging, common input parameters used in various analyses adjusted (rescaled) to values, known correlations taken into account. The include branching fractions, lifetimes, neutral meson mixing parameters, CP violation semileptonic...
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...
The only anticipated resonant contributions to ${B}^{+}\ensuremath{\rightarrow}{D}^{+}{D}^{\ensuremath{-}}{K}^{+}$ decays are charmonium states in the ${D}^{+}{D}^{\ensuremath{-}}$ channel. A model-independent analysis, using LHCb proton-proton collision data taken at center-of-mass energies of $\sqrt{s}=7$, 8, and 13 TeV, corresponding a total integrated luminosity $9\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, is carried out test this hypothesis. description assuming that resonances...
We search for the rare decay <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>B</a:mi><a:mo>+</a:mo></a:msup><a:mo stretchy="false">→</a:mo><a:msup><a:mi>K</a:mi><a:mo>+</a:mo></a:msup><a:mi>ν</a:mi><a:mover accent="true"><a:mi>ν</a:mi><a:mo stretchy="false">¯</a:mo></a:mover></a:math> in a <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"><f:mn>362</f:mn><f:mtext> </f:mtext><f:mtext>...
The doubly charmed baryon decay ${\mathrm{\ensuremath{\Xi}}}_{cc}^{++}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}_{c}^{+}{\ensuremath{\pi}}^{+}$ is observed for the first time, with a statistical significance of $5.9\ensuremath{\sigma}$, confirming recent observation in ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}$ final state. data sample used corresponds to an integrated luminosity $1.7\text{ }\text{...
From samples of $pp$ collision data collected by the LHCb experiment at $\sqrt{s}=7$, 8 and 13 TeV, corresponding to integrated luminosities 1.0, 2.0 $1.5\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, respectively, a peak in both ${\mathrm{\ensuremath{\Lambda}}}_{b}^{0}{K}^{\ensuremath{-}}$ ${\mathrm{\ensuremath{\Xi}}}_{b}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}$ invariant mass spectra is observed. In quark model, radially orbitally excited...
A study of the lineshape $\chi_{c1}(3872)$ state is made using a data sample corresponding to an integrated luminosity $3\,$fb$^{-1}$ collected in $pp$ collisions at centre-of-mass energies 7 and 8\,TeV with LHCb detector. Candidate $\psi(2S)$ mesons from b-hadron decays are selected $ J/\psi \pi^+ \pi^-$ decay mode. Describing {\mbox{lineshape}} Breit--Wigner function, mass splitting between states, $\Delta m$, width state, $\Gamma_{\mathrm{BW}}$, determined be \begin{eqnarray*} \Delta m &...
The first measurement of the lifetime doubly charmed baryon $\Xi_{cc}^{++}$ is presented, with signal reconstructed in final state $\Lambda_c^+ K^- \pi^+ \pi^+$. data sample used corresponds to an integrated luminosity $1.7\,\mathrm{fb}^{-1}$, collected by LHCb experiment proton-proton collisions at a centre-of-mass energy $13\mathrm{\,Te\kern -0.1em V}$. measured be $0.256\,^{+0.024}_{-0.022}{\,\rm (stat)\,} \pm 0.014 {\,\rm(syst)}\mathrm{\,ps}$.
The production fractions of $\overline{B}_s^0$ and $\Lambda_b^0$ hadrons, normalized to the sum $B^-$ $\overline{B}^0$ fractions, are measured in 13 TeV pp collisions using data collected by LHCb experiment, corresponding an integrated luminosity 1.67/fb. These ratios, averaged over $b$-hadron transverse momenta from 4 25 GeV pseudorapidity 2 5, $0.122 \pm 0.006$ for $\overline{B}_s^0$, $0.259 0.018$ $\Lambda_b^0$, where uncertainties arise both statistical systematic sources. ratio depends...
We report four narrow peaks in the Ξ_{b}^{0}K^{-} mass spectrum obtained using pp collisions at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity 9 fb^{-1} recorded by LHCb experiment. Referring these states their mass, values are m[Ω_{b}(6316)^{-}]=6315.64±0.31±0.07±0.50 MeV, m[Ω_{b}(6330)^{-}]=6330.30±0.28±0.07±0.50 m[Ω_{b}(6340)^{-}]=6339.71±0.26±0.05±0.50 m[Ω_{b}(6350)^{-}]=6349.88±0.35±0.05±0.50 where uncertainties statistical, systematic, last...
A bstract The decays B + → J / ψπ π − K are studied using a data set corresponding to an integrated luminosity of 9 fb 1 collected with the LHCb detector in proton-proton collisions between 2011 and 2018. Precise measurements ratios branching fractions intermediate ψ 2 (3823), χ c1 (3872) ψ(2S) states reported. values $$ {\displaystyle \begin{array}{c}\frac{{\mathcal{B}}_{{\mathrm{B}}^{+}\to {\uppsi}_2(3823){\mathrm{K}}^{+}}\times {\mathcal{B}}_{\uppsi_2(3823)\to \mathrm{J}/{\uppsi...
The production of J/$ψ$ mesons is studied in proton-lead collisions at the centre-of-mass energy per nucleon pair $\sqrt{s_{\text{NN}}}=8.16$ TeV with LHCb detector LHC. double differential cross-sections prompt and nonprompt are measured as functions transverse momentum rapidity nucleon-nucleon frame. Forward-to-backward ratios nuclear modification factors determined. results compared theoretical calculations based on collinear factorisation using parton distribution functions, colour glass...