O. Grachov
A5066490170- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Nuclear reactor physics and engineering
- Cosmology and Gravitation Theories
- Nuclear physics research studies
- Particle Accelerators and Free-Electron Lasers
- Astrophysics and Cosmic Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
- Radiation Detection and Scintillator Technologies
- Computational Physics and Python Applications
- Neutrino Physics Research
- Atomic and Subatomic Physics Research
- Atomic and Molecular Physics
- Nuclear Physics and Applications
- Markov Chains and Monte Carlo Methods
- Electron and X-Ray Spectroscopy Techniques
- Particle accelerators and beam dynamics
- Advanced Frequency and Time Standards
- Cold Atom Physics and Bose-Einstein Condensates
- Statistical Methods and Bayesian Inference
Wayne State University
2001-2024
HUN-REN Wigner Research Centre for Physics
2018
Hungarian Academy of Sciences
2018
A. Alikhanyan National Laboratory
2015-2017
Yale University
2016-2017
University of Kansas
2006-2014
UCLouvain
2011-2013
Institute of High Energy Physics
2010-2012
European Organization for Nuclear Research
2012
Austrian Academy of Sciences
2012
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
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...
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.
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.
Abstract We propose in this White Paper a concept for space experiment using cold atoms to search ultra-light dark matter, and detect gravitational waves the frequency range between most sensitive ranges of LISA terrestrial LIGO/Virgo/KAGRA/INDIGO experiments. This interdisciplinary experiment, called Atomic Experiment Dark Matter Gravity Exploration (AEDGE), will also complement other planned searches exploit synergies with wave detectors. give examples extended sensitivity matter offered...
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...
We present a systematic analysis of two-pion interferometry in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=200\phantom{\rule{0.3em}{0ex}}\mathrm{GeV}$ using the STAR detector Relativistic Heavy Ion Collider. extract Hanbury-Brown and Twiss radii study their multiplicity, transverse momentum, azimuthal angle dependence. The Gaussianness correlation function is studied. Estimates geometrical dynamical structure freeze-out source are extracted by fits with blast-wave...
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...
Midrapidity open charm spectra from direct reconstruction of ${D}^{0}(\overline{{D}^{0}})\ensuremath{\rightarrow}{K}^{\ensuremath{\mp}}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ in $d+\mathrm{A}\mathrm{u}$ collisions and indirect electron-positron measurements via semileptonic decays $p+p$ at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$ are reported. The ${D}^{0}(\overline{{D}^{0}})$ spectrum covers a transverse momentum (${p}_{T}$) range $0.1<{p}_{T}<3\text{...
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 short-lived $K(892){}^{*}$ resonance provides an efficient tool to probe properties of the hot and dense medium produced in relativistic heavy-ion collisions. We report measurements ${K}^{*}$ $\sqrt{{s}_{\mathit{NN}}}=200\phantom{\rule{0.3em}{0ex}}\mathrm{GeV}$ Au+Au $p+p$ collisions reconstructed via its hadronic decay channels $K(892){}^{*0}\ensuremath{\rightarrow}K\ensuremath{\pi}$...
Abstract We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning status of cold atom technologies, prospective scientific and societal opportunities offered by their deployment space, developments needed before atoms could be operated space. The technologies discussed include atomic clocks, quantum gravimeters accelerometers, interferometers. Prospective applications metrology, geodesy measurement terrestrial mass change due to, e.g., climate change,...
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...