A5105764616- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- Nuclear reactor physics and engineering
- Stochastic processes and statistical mechanics
- Nuclear physics research studies
- X-ray Spectroscopy and Fluorescence Analysis
- Particle Detector Development and Performance
- Markov Chains and Monte Carlo Methods
- Dark Matter and Cosmic Phenomena
- Statistical Methods and Bayesian Inference
- Theoretical and Computational Physics
- Superconducting Materials and Applications
- Atomic and Molecular Physics
- Pulsars and Gravitational Waves Research
- Census and Population Estimation
- Fusion materials and technologies
- Particle Accelerators and Free-Electron Lasers
- Laser-induced spectroscopy and plasma
- Electron and X-Ray Spectroscopy Techniques
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Pediatric Urology and Nephrology Studies
- Urological Disorders and Treatments
- Statistical Mechanics and Entropy
Yale University
2016-2025
Ball State University
2023-2024
University of Houston
2023-2024
Argonne National Laboratory
2020-2024
A. Alikhanyan National Laboratory
2015-2024
University of California, Riverside
2024
Eötvös Loránd University
2024
Central China Normal University
2022-2023
Abilene Christian University
2019-2023
Stony Brook University
2018-2023
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...
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 ${p}_{T}$,...
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...
Global polarization of $\Lambda$ hyperons has been measured to be the order a few tenths percent in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV, with no significant difference between and $\bar{\Lambda}$. These new results reveal collision energy dependence global together previously observed 7.7 -- 62.4 GeV indicate noticeable vorticity medium created non-central heavy-ion highest RHIC energy. The signal is rough quantitative agreement theoretical predictions from hydrodynamic model...
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...
Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y=0) are reported in sNN=7.7, 11.5, 19.6, 27, 39, 62.4, 200 GeV Au+Au collisions as recorded by the STAR detector at Relativistic Heavy Ion Collider. At intermediate impact parameters, proton net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 19.6 GeV. In addition, changes sign twice 7.7 39 The results qualitatively resemble predictions of hydrodynamic model with...
We report the first measurement of charmed-hadron (D(0)) production via hadronic decay channel (D(0) → K(-) + π(+)) in Au+Au collisions at sqrt[s(NN)] = 200 GeV with STAR experiment. The charm cross section per nucleon-nucleon collision midrapidity scales number binary collisions, N(bin), from p+p to central collisions. D(0) meson yields Au are strongly suppressed compared those scaled by for transverse momenta p(T) > 3 GeV/c, demonstrating significant energy loss quarks hot and dense...
Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local manifest themselves as charge separation along the magnetic field axis via chiral effect. experimental observation of previously reported for collisions at top RHIC energies. In this Letter, we present results beam-energy dependence correlations $\mathrm{Au}+\mathrm{Au}$ midrapidity center-of-mass energies 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from...
The Λ (Λ[over ¯]) hyperon polarization along the beam direction has been measured in Au+Au collisions at sqrt[s_{NN}]=200 GeV, for first time heavy-ion collisions. dependence on hyperons' emission angle relative to elliptic flow plane exhibits a second harmonic sine modulation, indicating quadrupole pattern of vorticity component direction, expected due flow. is found increase more peripheral collisions, and shows no strong transverse momentum (p_{T}) p_{T} greater than 1 GeV/c. magnitude...
Non-monotonic variation with collision energy ($\sqrt{s_{\rm NN}}$) of the moments net-baryon number distribution in heavy-ion collisions, related to correlation length and susceptibilities system, is suggested as a signature for Quantum Chromodynamics (QCD) critical point. We report first evidence non-monotonic kurtosis times variance net-proton (proxy number) function \rootsnn 3.1$\sigma$ significance, head-on (central) gold-on-gold (Au+Au) collisions measured using STAR detector at RHIC....
The Breit-Wheeler process which produces matter and anti-matter from photon collisions is investigated experimentally through the observation of 6085 exclusive electron-positron pairs in ultra-peripheral Au+Au at $\sqrt{s_{_{NN}}}=200$ GeV. measurements reveal a large fourth-order angular modulation $\cos{4\Delta\phi}=(16.8\pm2.5)\%$ smooth invariant mass distribution absent vector mesons ($\phi$, $\omega$ $\rho$) experimental limit $\le 0.2\%$ observed yields. differential cross section as...
We report a systematic measurement of cumulants, $C_{n}$, for net-proton, proton and antiproton multiplicity distributions, correlation functions, $\kappa_n$, distributions up to the fourth order in Au+Au collisions at $\sqrt{s_{\mathrm {NN}}}$ = 7.7, 11.5, 14.5, 19.6, 27, 39, 54.4, 62.4 200 GeV. The $C_{n}$ $\kappa_n$ are presented as function collision energy, centrality kinematic acceptance rapidity, $y$, transverse momentum, $p_{T}$. data were taken during first phase Beam Energy Scan...
This White Paper presents an overview of the current status and future perspective QCD research, based on community inputs scientific conclusions from 2022 Hot Cold Town Meeting. We present progress made in last decade toward a deep understanding both fundamental structure sub-atomic matter nucleon nucleus cold QCD, hot heavy ion collisions. identify key questions research plausible paths to obtaining answers those near future, hence defining priorities our over coming decades.
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...
We present the first measurements of identified hadron production, azimuthal anisotropy, and pion interferometry from $\mathrm{Au}+\mathrm{Au}$ collisions below nominal injection energy at BNL Relativistic Heavy-Ion Collider (RHIC) facility. The data were collected using large acceptance solenoidal tracker RHIC (STAR) detector $\sqrt{{s}_{\mathit{NN}}}=9.2$ GeV a test run collider in year 2008. Midrapidity results on multiplicity density $\mathit{dN}/\mathit{dy}$ rapidity $y$, average...
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{...
We present the scaling properties of Lambda, Xi, and Omega in midrapidity Au+Au collisions at Brookhaven National Laboratory Relativistic Heavy Ion Collider sqrt[s_{NN}]=200 GeV. The yield multistrange baryons per participant nucleon increases from peripheral to central more rapidly than that indicating an increase strange-quark density matter produced. strange phase-space occupancy factor gamma_{s} approaches unity for most collisions. Moreover, nuclear modification factors p, Xi are...