R. Bellwied
A5028517010- 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
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- X-ray Spectroscopy and Fluorescence Analysis
- Stochastic processes and statistical mechanics
- Atomic and Molecular Physics
- Statistical Methods and Bayesian Inference
- Dark Matter and Cosmic Phenomena
- Nuclear Physics and Applications
- Markov Chains and Monte Carlo Methods
- CCD and CMOS Imaging Sensors
- Pulsars and Gravitational Waves Research
- Cosmology and Gravitation Theories
- Theoretical and Computational Physics
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Census and Population Estimation
- Nuclear Issues and Defense
- Laser-induced spectroscopy and plasma
- Particle Accelerators and Free-Electron Lasers
University of Houston
2016-2025
A. Alikhanyan National Laboratory
2014-2024
Universidad Nacional Autónoma de México
2011-2024
University of California, Riverside
2024
Wayne State University
2004-2021
Technical University of Munich
2021
University of Wuppertal
2016-2021
Rutgers, The State University of New Jersey
2019
AGH University of Krakow
2018-2019
Abilene Christian University
2019
ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, strong-interaction sector of Standard Model. It designed to address physics strongly interacting matter and quark-gluon plasma extreme values energy density temperature in nucleus-nucleus collisions. Besides running with Pb ions, programme includes collisions lighter lower dedicated proton-nucleus runs. will also take data proton beams top collect reference for several QCD...
Identified charged-particle spectra of ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}^{\ifmmode\pm\else\textpm\fi{}}$, $p$, and $\overline{p}$ at midrapidity ($|y|<0.1$) measured by the $\mathit{dE}/\mathit{dx}$ method in STAR (solenoidal tracker BNL Relativistic Heavy Ion Collider) time projection chamber are reported for $\mathit{pp}$ $d+\mathrm{Au}$ collisions $\sqrt{{s}_{\mathit{NN}}}=200$ GeV $\mathrm{Au}+\mathrm{Au}$ 62.4, 130, 200 GeV. Average transverse momenta, total...
We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with ALICE detector CERN Large Hadron Collider. The is performed central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. signal v₂, measured using 4-particle correlation method, averaged over 0.087 ± 0.002(stat) 0.003(syst) 40%-50% centrality class. differential v₂ p t reaches a maximum 0.2 near =3 Compared to RHIC Au-Au 200 GeV, increases by about...
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...
Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic charged particles at midrapidity in Au+Au square root(S)NN = 130 GeV using STAR Time Projection Chamber Relativistic Heavy Ion Collider. The signal, v2, averaged over transverse momentum, reaches values about 6% for relatively peripheral and decreases more central collisions. This can be interpreted as observation higher degree thermalization...
The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions sqrt[s_{NN}]=2.76 TeV is presented. normalized per participating nucleon pair increases by about a factor 2 from peripheral (70%-80%) to central (0%-5%) collisions. found be similar that observed lower collision energies. data are compared with models based on different mechanisms for particle production nuclear
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
In this paper measurements are presented of $\rm \pi$$^+$, \pi$$^-$, K$^+$, K$^-$, p and $\overline{\rm p}$ production at mid-rapidity < 0.5, in Pb-Pb collisions $\sqrt{s_{\rm NN}} = 2.76$ TeV as a function centrality. The measurement covers the transverse momentum ($p_{\rm T}$) range from 100, 200, 300 MeV/$c$ up to 3, 4.6 GeV/$c$, for $\rm\pi$, K, respectively. measured $p_{\rm T}$ distributions yields compared expectations based on hydrodynamic, thermal recombination models. spectral...
We report on the first measurement of triangular ${v}_{3}$, quadrangular ${v}_{4}$, and pentagonal ${v}_{5}$ charged particle flow in Pb-Pb collisions at $\sqrt{{s}_{\mathrm{NN}}}=2.76\text{ }\text{ }\mathrm{TeV}$ measured with ALICE detector CERN Large Hadron Collider. show that can be described terms initial spatial anisotropy its fluctuations, which provides strong constraints origin. In most central events, where elliptic ${v}_{2}$ ${v}_{3}$ have similar magnitude, a double peaked...
The results from the STAR Collaboration on directed flow (${v}_{1}$), elliptic (${v}_{2}$), and fourth harmonic (${v}_{4}$) in anisotropic azimuthal distribution of particles Au+Au collisions at $\sqrt{{s}_{\mathit{NN}}}=200\phantom{\rule{0.3em}{0ex}}\mathrm{GeV}$ are summarized compared with other experiments theoretical models. Results for identified presented fit a blast-wave model. Different analysis methods nonflow effects extracted data. For ${v}_{2}$, scaling number constituent quarks...
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...
Inclusive transverse momentum spectra of primary charged particles in Pb–Pb collisions at sNN=2.76TeV have been measured by the ALICE Collaboration LHC. The data are presented for central and peripheral collisions, corresponding to 0–5% 70–80% hadronic cross section. particle |η|<0.8 0.3<pT<20GeV/c compared expectation pp same sNN, scaled number underlying nucleon–nucleon collisions. comparison is expressed terms nuclear modification factor RAA. result indicates only weak medium effects...
Parity-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted lead charge separation quarks along system's orbital momentum axis. We investigate a three-particle azimuthal correlator which is $\mathcal{P}$ even observable, but directly sensitive effect. report measurements charged hadrons near center-of-mass rapidity with this observable in $\mathrm{Au}+\mathrm{Au}$ and...
We present measurements of bulk properties the matter produced in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 11.5, 19.6, 27, and 39 GeV using identified hadrons ($\pi^\pm$, $K^\pm$, $p$ $\bar{p}$) from STAR experiment Beam Energy Scan (BES) Program Relativistic Heavy Ion Collider (RHIC). Midrapidity ($|y|<$0.1) results for multiplicity densities $dN/dy$, average transverse momenta $\langle p_T \rangle$ particle ratios are presented. The chemical kinetic freeze-out dynamics these energies...
Charged hadrons in [EQUATION: SEE TEXT] associated with particles of are reconstructed pp and Au+Au collisions at sqrt[sNN]=200 GeV. The multiplicity p magnitude sum found to increase from central collisions. distributions, while similar shape on the nearside, significantly softened awayside relative not much harder than that inclusive hadrons. results, consistent jet quenching, suggest fragments approach equilibration medium traversed.
We report the beam energy (sqrt[sNN]=7.7-200 GeV) and collision centrality dependence of mean (M), standard deviation (σ), skewness (S), kurtosis (κ) net-proton multiplicity distributions in Au+Au collisions. The measurements are carried out by STAR experiment at midrapidity (|y|<0.5) within transverse momentum range 0.4<pT<0.8 GeV/c first phase Beam Energy Scan program Relativistic Heavy Ion Collider. These important for understanding quantum chromodynamic diagram. products moments, Sσ κσ2,...
The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of inclusive yield nonphotonic electrons, which arise dominantly from semileptonic decays heavy flavor mesons, over a broad range transverse momenta ($1.2<{p}_{T}<10\text{ }\text{ }\mathrm{GeV}/c$) in $p+p$, $d+\mathrm{Au}$, and $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{\mathrm{NN}}}=200\text{ }\mathrm{GeV}$. electron exhibits an unexpectedly large suppression central high ${p}_{T}$,...
This publication describes the methods used to measure centrality of inelastic Pb-Pb collisions at a center-of-mass energy 2.76 TeV per colliding nucleon pair with ALICE. The is key parameter in study properties QCD matter extreme temperature and density, because it directly related initial overlap region nuclei. Geometrical collision, such as number participating nucleons binary nucleon-nucleon collisions, are deduced from Glauber model sharp impact selection shown be consistent those...
The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions a center-of-mass energy per nucleon pair $\sqrt{{s}_{NN}}=2.76\text{ }\text{ }\mathrm{TeV}$ is presented. For an event sample corresponding to most central 5% hadronic cross section, pseudorapidity primary charged particles $1584\ifmmode\pm\else\textpm\fi{}4(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}76(\mathrm{syst})$, which corresponds $8.3\ifmmode\pm\else\textpm\fi{}0.4(\mathrm{syst})$...
We present strange particle spectra and yields measured at midrapidity in $\sqrt{s}=200$ GeV proton-proton ($p+p$) collisions the BNL Relativistic Heavy Ion Collider (RHIC). find that previously observed universal transverse mass (${m}_{T}\ensuremath{\equiv}\sqrt{{{p}_{T}}^{2}+{m}^{2}}$) scaling of hadron production $p+p$ seems to break down higher ${m}_{T}$ there is a difference shape spectrum between baryons mesons. observe antibaryon baryon ratios near unity for \ensuremath{\Lambda}...
Parity ($\mathcal{P}$)-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted lead charge separation quarks along orbital momentum system in noncentral To study this effect, we investigate a three-particle mixed-harmonics azimuthal correlator which is $\mathcal{P}$-even observable, but directly sensitive charge-separation effect. We report measurements observable using STAR...