J. Balewski
A5065230562- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- Nuclear reactor physics and engineering
- Nuclear physics research studies
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Quantum Computing Algorithms and Architecture
- X-ray Spectroscopy and Fluorescence Analysis
- Atomic and Molecular Physics
- Advanced Data Storage Technologies
- Stochastic processes and statistical mechanics
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum Information and Cryptography
- Particle Accelerators and Free-Electron Lasers
- Quantum-Dot Cellular Automata
- Markov Chains and Monte Carlo Methods
- Distributed and Parallel Computing Systems
- Advanced Neural Network Applications
- Quantum Mechanics and Applications
- Scientific Computing and Data Management
- Atomic and Subatomic Physics Research
- Quantum and electron transport phenomena
- Superconducting Materials and Applications
- Genomics and Phylogenetic Studies
National Energy Research Scientific Computing Center
2017-2024
Lawrence Berkeley National Laboratory
2017-2024
Massachusetts Institute of Technology
2010-2021
Indian Institute of Technology Bombay
2011
Indiana University Bloomington
2000-2008
Indiana University
1999-2002
Institute of Physics
1991-1995
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 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...
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...
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...
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 ${p}_{T}$,...
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.
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...
We report the first measurements of kurtosis (\kappa), skewness (S) and variance (\sigma^2) net-proton multiplicity (N_p - N_pbar) distributions at midrapidity for Au+Au collisions \sqrt(s_NN) = 19.6, 62.4, 200 GeV corresponding to baryon chemical potentials (\mu_B) between 20 MeV. Our products \kappa \sigma^2 S \sigma, which can be related theoretical calculations sensitive number susceptibilities long range correlations, are constant as functions collision centrality. compare these with...
We report the first measurements of moments -- mean ($M$), variance ($\sigma^{2}$), skewness ($S$) and kurtosis ($\kappa$) net-charge multiplicity distributions at mid-rapidity in Au+Au collisions seven energies, ranging from $\sqrt {{s_{\rm NN}}}$= 7.7 to 200 GeV, as a part Beam Energy Scan program RHIC. The are related thermodynamic susceptibilities net-charge, sensitive proximity QCD critical point. compare products moments, $\sigma^{2}/M$, $S\sigma$ $\kappa\sigma^{2}$ with expectations...
The STAR Collaboration at the Relativistic Heavy Ion Collider presents a systematic study of high-transverse-momentum charged-di-hadron correlations small azimuthal pair separation $\ensuremath{\Delta}\ensuremath{\phi}$ in $d+\mathrm{Au}$ and central $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{\mathit{NN}}}=200$ GeV. Significant correlated yield for pairs with large longitudinal $\ensuremath{\Delta}\ensuremath{\eta}$ is observed collisions, contrast to collisions. associated...
Nuclear collisions recreate conditions in the universe microseconds after Big Bang. Only a very small fraction of emitted fragments are light nuclei, but these states fundamental interest. We report observation antihypertritons - composed an antiproton, antineutron, and antilambda hyperon produced by colliding gold nuclei at high energy. Our analysis yields 70 +- 17 157 30 hypertritons. The measured hypertriton (antihypertriton) helium3 (antihelium3) similar, suggesting equilibrium...
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 sqrt(s_NN)=130 GeV using STAR TPC RHIC. The signal, v_2, 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 than lower collision energies. Pseudorapidity momentum...
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...
Transverse momentum spectra of pi+/-, p, and p up to 12 GeV/c at midrapidity in centrality selected Au + collisions square root sNN=200 GeV are presented. In central collisions, both pi +/- p(p) show significant suppression with respect binary scaling pT approximately >4 GeV/c. Protons antiprotons less suppressed than the range 1.5 < 6 The pi-/pi+ p/p ratios most a weak dependence no dependence. p/pi approach values d >5 results high indicate that partonic sources have similar energy loss...
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...