M. Germain
A5000571972- 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
- GaN-based semiconductor devices and materials
- Nuclear physics research studies
- Semiconductor materials and devices
- Dark Matter and Cosmic Phenomena
- Radio Frequency Integrated Circuit Design
- Atomic and Molecular Physics
- Silicon Carbide Semiconductor Technologies
- X-ray Spectroscopy and Fluorescence Analysis
- Ga2O3 and related materials
- Cosmology and Gravitation Theories
- Stochastic processes and statistical mechanics
- Radiation Detection and Scintillator Technologies
- Radiation Effects in Electronics
- Statistical Methods and Bayesian Inference
- Nuclear Physics and Applications
- Advancements in Semiconductor Devices and Circuit Design
- Stellar, planetary, and galactic studies
- Semiconductor Quantum Structures and Devices
- Metal and Thin Film Mechanics
- Acoustic Wave Resonator Technologies
IMT Atlantique
2017-2025
Laboratoire de Physique Subatomique et des Technologies Associées
2016-2025
Nantes Université
2016-2025
Institut National de Physique Nucléaire et de Physique des Particules
2002-2025
Centre National de la Recherche Scientifique
2016-2025
A. Alikhanyan National Laboratory
2015-2024
Technical University of Munich
2021
Budker Institute of Nuclear Physics
2020
Aligarh Muslim University
2020
Center for Research and Advanced Studies of the National Polytechnic Institute
2020
We report high statistics measurements of inclusive charged hadron production in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. A large, approximately constant suppression is observed central for 5<p(T)<12 GeV/c. The collision energy dependence the yields centrality p(T) provide stringent constraints on theoretical models suppression. Models incorporating initial-state gluon saturation or partonic loss dense matter are largely consistent with observations. observe no evidence...
Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudorapidity range and full azimuth in Au+Au p+p collisions at sqrt[s(NN)]=200 GeV. The small-angle observed all centralities of are characteristic hard-scattering processes previously high-energy collisions. A strong back-to-back correlation exists peripheral Au+Au. In contrast, the reduced considerably most central collisions, indicating substantial interaction as hard-scattered partons or...
We report measurements of single-particle inclusive spectra and two-particle azimuthal distributions charged hadrons at high transverse momentum (high p(T)) in minimum bias central d+Au collisions sqrt[s(NN)]=200 GeV. The yield is enhanced relative to binary-scaled p+p collisions, while the are very similar those observed collisions. These results demonstrate that strong suppression back-to-back correlations p(T) previously Au+Au due final-state interactions with dense medium generated such
Inclusive transverse momentum distributions of charged hadrons within 0.2<p(T)<6.0 GeV/c have been measured over a broad range centrality for Au+Au collisions at sqrt[s(NN)]=130 GeV. Hadron yields are suppressed high p(T) in central relative to peripheral and nucleon-nucleon reference scaled collision geometry. Peripheral not the reference. The suppression varies continuously intermediate centralities. results indicate significant nuclear medium effects on high-p(T) hadron production...
We present STAR measurements of the azimuthal anisotropy parameter v(2) and binary-collision scaled centrality ratio R(CP) for kaons lambdas (Lambda+Lambda) at midrapidity in Au+Au collisions square root s(NN)=200 GeV. In combination, particle-type dependencies contradict expectations from partonic energy loss followed by standard fragmentation vacuum. establish p(T) approximately 5 GeV/c as value where dependent baryon enhancement ends. The K(0)(S) Lambda+Lambda values are consistent with...
The third US Naval Observatory (USNO) CCD Astrograph Catalog, UCAC3 was released at the IAU General Assembly on 2009 August 10. It is first all-sky release in this series and contains just over 100 million objects, about 95 of them with proper motions, covering R = 8 to 16 magnitudes. Current epoch positions are obtained from observations 20 cm aperture USNO Astrograph's "red lens", equipped a 4k by CCD. Proper motions derived combining these 140 ground- space-based catalogs, including...
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.
Transverse mass and rapidity distributions for charged pions, kaons, protons, antiprotons are reported square root of [sNN]=200 GeV pp Au+Au collisions at Relativistic Heary Ion Collider (RHIC). Chemical kinetic equilibrium model fits to our data reveal strong radial flow long duration from chemical freeze-out in central collisions. The temperature appears be independent initial conditions RHIC energies.
Context. PIONIER stands for Precision Integrated-Optics Near-infrared Imaging ExpeRiment. It combines four 1.8m Auxilliary Telescopes or 8m Unit of the Very Large Telescope Interferometer (ESO, Chile) using an integrated optics combiner. The instrument was at IPAG in December 2009 and commissioned Paranal Observatory October 2010. has provided scientific observations since November
Elliptic flow holds much promise for studying the early-time thermalization attained in ultrarelativistic nuclear collisions. Flow measurements also provide a means of distinguishing between hydrodynamic models and calculations which approach low density (dilute gas) limit. Among effects that can complicate interpretation elliptic are azimuthal correlations unrelated to reaction plane (non-flow correlations). Using data Au + collisions at sqrt{s_{NN}} = 130 GeV from STAR TPC, it is found...
We report first results on elliptic flow of identified particles at midrapidity in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{\mathrm{NN}}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}130\mathrm{GeV}$ using the STAR TPC RHIC. The as a function transverse momentum and centrality differs significantly for different masses. This dependence can be accounted hydrodynamic models, indicating that system created shows behavior consistent with collective hydrodynamical flow. fit to data...
Measurements of the production forward high-energy ${\ensuremath{\pi}}^{0}$ mesons from transversely polarized proton collisions at $\sqrt{s}=200\text{ }\text{ }\mathrm{GeV}$ are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. analyzing power small ${x}_{F}$ below about 0.3, and becomes positive large higher ${x}_{F}$, similar to trend in data $\sqrt{s}\ensuremath{\le}20\text{ }\mathrm{GeV}$. qualitative agreement model...
Two-pion correlation functions in Au+Au collisions at $\sqrt{s_{NN}} = 130$ GeV have been measured by the STAR (Solenoidal Tracker RHIC) detector. The source size extracted fitting correlations grows with event multiplicity and decreases transverse momentum. Anomalously large sizes or emission durations, which suggested as signals of quark-gluon plasma formation rehadronization, are not observed. HBT parameters display a weak energy dependence over broad range $\sqrt{s_{NN}}$.
We report the first observations of harmonic (directed flow, ${v}_{1}$) and fourth (${v}_{4}$), in azimuthal distribution particles with respect to reaction plane $\mathrm{A}\mathrm{u}+\mathrm{A}\mathrm{u}$ collisions at BNL Relativistic Heavy Ion Collider (RHIC). Both measurements were done taking advantage large elliptic flow (${v}_{2}$) generated RHIC. From correlation ${v}_{2}$ ${v}_{1}$ it is determined that positive, or in-plane. The integrated ${v}_{4}$ about a factor 10 smaller than...
We report the STAR measurement of ϕ meson production in Au+Au and p+p collisions at sNN=200GeV. Using event mixing technique, spectra yields are obtained mid-rapidity for five centrality bins non-singly-diffractive collisions. It is found that transverse momentum distributions from better fitted with a single-exponential while spectrum described by double-exponential distribution. The measured nuclear modification factors indicate central suppressed relative to peripheral when scaled number...
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...
Azimuthal anisotropy (v(2)) and two-particle angular correlations of high p(T) charged hadrons have been measured in Au+Au collisions at sqrt[s(NN)]=130 GeV for transverse momenta up to 6 GeV/c, where hard processes are expected contribute significantly. The exhibit elliptic flow a structure suggestive fragmentation partons. monotonic rise v(2)(p(T)) p(T)<2 GeV/c is consistent with collective hydrodynamical calculations. At p(T)>3 saturation v(2) observed which persists p(T)=6 GeV/c.
The minimum-bias multiplicity distribution and the transverse momentum pseudorapidity distributions for central collisions have been measured negative hadrons ( h(-)) in Au+Au interactions at square root of ([s(NN)]) = 130 GeV. density midrapidity 5% most is dN(h(-))/d(eta)/(eta 0) 280+/-1(stat)+/-20(syst), an increase per participant 38% relative to pp same energy. mean 0.508+/-0.012 GeV/c larger than Pb+Pb lower energies. scaling h(-) yield a strong function p( perpendicular). almost...
We report the first measurement of strange (Lambda) and antistrange (Lambda macro) baryon production from square root [s(NN)]=130 GeV Au+Au collisions at Relativistic Heavy Ion Collider (RHIC). Rapidity density transverse mass distributions midrapidity are presented as a function centrality. The yield Lambda Lambda; hyperons is found to be approximately proportional number negative hadrons. relative hadrons increases very rapidly with momentum. magnitude increase cannot described by existing...
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...
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)...