B. Espagnon
A5046446846- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- Dark Matter and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Muon and positron interactions and applications
- Particle Accelerators and Free-Electron Lasers
- Statistical Methods and Bayesian Inference
- Atomic and Subatomic Physics Research
- Cosmology and Gravitation Theories
- Silicon Carbide Semiconductor Technologies
- Particle accelerators and beam dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Stochastic processes and statistical mechanics
- Computational Physics and Python Applications
- Radiation Effects in Electronics
- High voltage insulation and dielectric phenomena
- Chemical Synthesis and Characterization
- Analytical chemistry methods development
- advanced mathematical theories
- Advanced Frequency and Time Standards
Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2020-2025
Institut National de Physique Nucléaire et de Physique des Particules
2014-2025
Centre National de la Recherche Scientifique
2014-2025
Université Paris-Saclay
2009-2025
A. Alikhanyan National Laboratory
2014-2024
Institut de Physique
2013-2022
Aligarh Muslim University
2022
Technical University of Munich
2021
Université Paris-Sud
2010-2019
Istituto Nazionale di Fisica Nucleare, Sezione di Torino
2011-2016
The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured electrons with $0.3<{p}_{T}<9\text{ }\text{ }\mathrm{GeV}/c$ midrapidity ($|y|<0.35$) from heavy-flavor (charm and bottom) decays in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{\mathrm{NN}}}=200\text{ }\mathrm{GeV}$. nuclear modification factor ${R}_{\mathrm{AA}}$ relative to $p+p$ shows a strong suppression central collisions, indicating substantial energy loss of heavy quarks medium produced RHIC...
Transverse momentum spectra of charged hadrons with p(T)<8 GeV/c and neutral pions p(T)<10 have been measured at midrapidity by the PHENIX experiment BNL RHIC in d+Au collisions sqrt[s(NN)]=200 GeV. The yields are compared to those p+p same sqrt[s(NN)] scaled up number underlying nucleon-nucleon d+Au. yield ratio does not show suppression observed central Au+Au RHIC. Instead, there is a small enhancement high particles.
The production of low mass e+e- pairs for m_{e+e-} < 300 MeV/c^2 and 1 p_T <5 GeV/c is measured in p+p Au+Au collisions at sqrt(s_NN)=200 GeV. Enhanced yield above hadronic sources observed. Treating the excess as internal conversions, invariant direct photons deduced. In central collisions, photon over exponential transverse momentum, with inverse slope T = 221 +/- 19 (stat) (syst) MeV. Hydrodynamical models initial temperatures ranging from 300--600 MeV times ~ 0.6 - 0.15 fm/c after...
The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC)has measured $J/\ensuremath{\psi}$ production for rapidities $\ensuremath{-}2.2<y<2.2$ in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$. invariant yield and nuclear modification factor ${R}_{AA}$ as a function of centrality,transverse momentum, rapidity are reported. A suppression relative to binary collision scaling proton-protonreaction yields is observed. Models which describe...
Differential measurements of elliptic flow (${v}_{2}$) for $\mathrm{Au}+\mathrm{Au}$ and $\mathrm{Cu}+\mathrm{Cu}$ collisions at $\sqrt{{s}_{\mathrm{NN}}}=200\text{ }\text{ }\mathrm{GeV}$ are used to test validate predictions from perfect fluid hydrodynamics scaling ${v}_{2}$ with eccentricity, system size, transverse kinetic energy (${\mathrm{KE}}_{T}$). For ${\mathrm{KE}}_{T}\ensuremath{\equiv}{m}_{T}\ensuremath{-}m$ up $\ensuremath{\sim}1\text{ the is compatible hydrodynamic expansion a...
Azimuthal angle ($\ensuremath{\Delta}\ensuremath{\phi}$) correlations are presented for a broad range of transverse momentum ($0.4<{p}_{T}<10$ GeV/$c$) and centrality (0--92%) selections charged hadrons from dijets in Au+Au collisions at $\sqrt{{s}_{\mathit{NN}}}=200$ GeV. With increasing ${p}_{T}$, the away-side $\ensuremath{\Delta}\ensuremath{\phi}$ distribution evolves relatively flat shape to concave shape, then convex shape. Comparisons with $p+p$ data suggest that can be divided into...
For Au + collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, pT, up to 20 GeV/c. A fivefold suppression is found, which essentially constant 5 < pT Experimental uncertainties are small enough constrain any model-dependent parametrization the transport coefficient of medium, e.g., q in parton quenching model. The spectral shape similar all collision classes, and does not saturate collisions.
PHENIX has measured the e^+e^- pair continuum in sqrt(s_NN)=200 GeV Au+Au and p+p collisions over a wide range of mass transverse momenta. The yield is compared to expectations from hadronic sources, based on measurements. In intermediate region, between masses phi J/psi meson, consistent with correlated c^bar-c production, though other mechanisms are not ruled out. low region (below phi) inclusive spectrum well described by known contributions light meson decays. contrast, minimum bias this...
Transverse momentum spectra of electrons (${p}_{T}^{e}$) from semileptonic weak decays heavy-flavor mesons in the range $0.3<{p}_{T}^{e}<9.0$ GeV/$c$ have been measured at midrapidity ($|y|<0.35$) by PHENIX experiment Relativistic Heavy Ion Collider $p+p$ and $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{\mathrm{NN}}}=200$ GeV. In addition, azimuthal anisotropy parameter ${v}_{2}$ has for $0.3<{p}_{T}^{e}<5.0$ collisions. The substantial modification ${p}_{T}^{e}$ compared with as well...
The dependence of transverse momentum spectra neutral pions and $\ensuremath{\eta}$ mesons with ${p}_{T}<16\text{ }\text{ }\mathrm{GeV}/c$ ${p}_{T}<12\text{ }\mathrm{GeV}/c$, respectively, on the centrality collision has been measured at midrapidity by PHENIX experiment BNL Relativistic Heavy Ion Collider (RHIC) in $d+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=200\text{ }\mathrm{GeV}$. yields are compared to those $p+p$ same $\sqrt{{s}_{NN}}$ scaled number underlying nucleon-nucleon...
Cross sections for midrapidity production of direct photons in p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are reported transverse momenta 3 < pT 16 GeV/c. Next-to-leading order perturbative QCD (pQCD) describes data well >5 GeV/c, where uncertainties measurement and theory comparable. We also report on effect requiring to be isolated from parton jet energy. The observed fraction is described by pQCD >7
$J/\ensuremath{\psi}$ production in $d+\mathrm{Au}$ and $p+p$ collisions at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$ has been measured by the PHENIX experiment rapidities $\ensuremath{-}2.2<y<+2.4$. The cross sections nuclear dependence of versus rapidity, transverse momentum, centrality are obtained compared to lower energy $p+A$ results theoretical models. observed is found be modest, suggesting that absorption final state weak shadowing gluon distributions small consistent with...
Differential elliptic flow (${v}_{2}$) for $\ensuremath{\phi}$ mesons and (anti)deuterons $(\overline{d})d$ is measured $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$. The ${v}_{2}$ follows the trend of lighter ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ ${K}^{\ifmmode\pm\else\textpm\fi{}}$ mesons, suggesting that ordinary hadrons interacting with standard hadronic cross sections are not primary driver development. values suggest additive...
We present the first measurement of photoproduction J/ψ and two-photon production high-mass e+e− pairs in electromagnetic (or ultra-peripheral) nucleus–nucleus interactions, using Au + data at sNN=200 GeV. The events are tagged with forward neutrons emitted following Coulomb excitation one or both Au⋆ nuclei. event sample consists 28 me+e−>2 GeV/c2 zero like-sign background. measured cross sections midrapidity dσ/dy(J/ψ+Xn,y=0)=76±33(stat)±11(syst) μb...
The PHENIX experiment has measured the suppression of semi-inclusive single high-transverse-momentum ${\ensuremath{\pi}}^{0}$'s in Au+Au collisions at $\sqrt{{s}_{\mathit{NN}}}=200$ GeV. present understanding this is terms energy loss parent (fragmenting) parton a dense color-charge medium. We have performed quantitative comparison between various energy-loss models and our experimental data. statistical point-to-point uncorrelated as well correlated systematic uncertainties are taken into...
We present a new analysis of $J/\ensuremath{\psi}$ production yields in deuteron-gold collisions at $\sqrt{{s}_{\mathit{NN}}}=200$ GeV using data taken from the PHENIX experiment 2003 and previously published S. Adler et al. [Phys. Rev. Lett 96, 012304 (2006)]. The high statistics proton-proton 2005 are used to improve baseline measurement thus construct updated cold nuclear matter modification factors (${R}_{d\mathrm{Au}}$). A suppression is observed as one goes forward rapidity (in...
We report the measurement of direct photons at midrapidity in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$. The photon signal was extracted for transverse momentum range $4\text{ }\mathrm{GeV}/\phantom{\rule{0ex}{0ex}}c<{p}_{T}<22\text{ }\mathrm{GeV}/c$, using a statistical method to subtract decay from inclusive sample. nuclear modification factor ${R}_{\mathrm{AA}}$ calculated as function ${p}_{T}$ different collision centralities measured $p+p$...
We present inclusive charged hadron elliptic flow (${v}_{2}$) measured over the pseudorapidity range $|\ensuremath{\eta}|<0.35$ in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{\mathit{NN}}}=200$ GeV. Results for ${v}_{2}$ are presented a broad of transverse momentum $({p}_{T}=0.2\text{\ensuremath{-}}8.0$ GeV/$c$) and centrality (0--60%). To study nonflow effects that correlations other than collective flow, as well fluctuations ${v}_{2}$, we compare two different analysis methods: (1)...
Measurements of the midrapidity transverse energy distribution, $d\Et/d\eta$, are presented for $p$$+$$p$, $d$$+$Au, and Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV additionally $\sqrt{s_{_{NN}}}=62.4$ 130 GeV. The $d\Et/d\eta$ distributions first compared with number nucleon participants $N_{\rm part}$, binary coll}$, constituent-quark $N_{qp}$ calculated from a Glauber model based on nuclear geometry. For Au$+$Au, $\mean{d\Et/d\eta}/N_{\rm part}$ increases while...