A5043265102- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Nuclear reactor physics and engineering
- Dark Matter and Cosmic Phenomena
- Nuclear physics research studies
- Stochastic processes and statistical mechanics
- Pediatric Urology and Nephrology Studies
- CCD and CMOS Imaging Sensors
- Plasma Diagnostics and Applications
- Advancements in Semiconductor Devices and Circuit Design
- Advanced Data Storage Technologies
- Statistical Methods and Bayesian Inference
- Quantum, superfluid, helium dynamics
- Simulation Techniques and Applications
- Medical Imaging Techniques and Applications
- Laser Design and Applications
- Photocathodes and Microchannel Plates
- Magnetic confinement fusion research
- Silicon Carbide Semiconductor Technologies
- Nuclear Physics and Applications
- Pulsars and Gravitational Waves Research
- Atomic and Subatomic Physics Research
Brookhaven National Laboratory
2015-2024
Abilene Christian University
2023
Augustana University
2023
PHENIX laboratory
2023
Mississippi State University
2022
Japan Atomic Energy Agency
2016
University of Saskatchewan
2006
Massachusetts Institute of Technology
2006
Yale University
2006
Stony Brook University
2003
The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured electrons with $0.3<{p}_{T}<9\text{ }\text{ }\mathrm{GeV}/c$ midrapidity ($|y|<0.35$) from heavy-flavor (charm and bottom) decays in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{\mathrm{NN}}}=200\text{ }\mathrm{GeV}$. nuclear modification factor ${R}_{\mathrm{AA}}$ relative to $p+p$ shows a strong suppression central collisions, indicating substantial energy loss of heavy quarks medium produced RHIC...
The production of low mass e+e- pairs for m_{e+e-} < 300 MeV/c^2 and 1 p_T <5 GeV/c is measured in p+p Au+Au collisions at sqrt(s_NN)=200 GeV. Enhanced yield above hadronic sources observed. Treating the excess as internal conversions, invariant direct photons deduced. In central collisions, photon over exponential transverse momentum, with inverse slope T = 221 +/- 19 (stat) (syst) MeV. Hydrodynamical models initial temperatures ranging from 300--600 MeV times ~ 0.6 - 0.15 fm/c after...
The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC)has measured $J/\ensuremath{\psi}$ production for rapidities $\ensuremath{-}2.2<y<2.2$ in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$. invariant yield and nuclear modification factor ${R}_{AA}$ as a function of centrality,transverse momentum, rapidity are reported. A suppression relative to binary collision scaling proton-protonreaction yields is observed. Models which describe...
Differential measurements of elliptic flow (${v}_{2}$) for $\mathrm{Au}+\mathrm{Au}$ and $\mathrm{Cu}+\mathrm{Cu}$ collisions at $\sqrt{{s}_{\mathrm{NN}}}=200\text{ }\text{ }\mathrm{GeV}$ are used to test validate predictions from perfect fluid hydrodynamics scaling ${v}_{2}$ with eccentricity, system size, transverse kinetic energy (${\mathrm{KE}}_{T}$). For ${\mathrm{KE}}_{T}\ensuremath{\equiv}{m}_{T}\ensuremath{-}m$ up $\ensuremath{\sim}1\text{ the is compatible hydrodynamic expansion a...
Flow coefficients v_n for n = 2, 3, 4, characterizing the anisotropic collective flow in Au+Au collisions at sqrt(s_NN) 200 GeV, are measured relative to event planes \Psi_n determined large rapidity. We report as a function of transverse momentum and collision centrality, study correlations among different order n. The well described by hydrodynamic models which employ Glauber Monte Carlo initial state geometry with fluctuations, providing additional constraining power on interplay between...
Azimuthal angle ($\ensuremath{\Delta}\ensuremath{\phi}$) correlations are presented for a broad range of transverse momentum ($0.4<{p}_{T}<10$ GeV/$c$) and centrality (0--92%) selections charged hadrons from dijets in Au+Au collisions at $\sqrt{{s}_{\mathit{NN}}}=200$ GeV. With increasing ${p}_{T}$, the away-side $\ensuremath{\Delta}\ensuremath{\phi}$ distribution evolves relatively flat shape to concave shape, then convex shape. Comparisons with $p+p$ data suggest that can be divided into...
For Au + collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, pT, up to 20 GeV/c. A fivefold suppression is found, which essentially constant 5 < pT Experimental uncertainties are small enough constrain any model-dependent parametrization the transport coefficient of medium, e.g., q in parton quenching model. The spectral shape similar all collision classes, and does not saturate collisions.
PHENIX has measured the e^+e^- pair continuum in sqrt(s_NN)=200 GeV Au+Au and p+p collisions over a wide range of mass transverse momenta. The yield is compared to expectations from hadronic sources, based on measurements. In intermediate region, between masses phi J/psi meson, consistent with correlated c^bar-c production, though other mechanisms are not ruled out. low region (below phi) inclusive spectrum well described by known contributions light meson decays. contrast, minimum bias this...
The PHENIX collaboration at the Relativistic Heavy Ion Collider (RHIC) reports measurements of azimuthal dihadron correlations near midrapidity in $d$$+$Au collisions $\sqrt{s_{_{NN}}}$=200 GeV. These complement recent analyses by experiments Large Hadron (LHC) involving central $p$$+$Pb $\sqrt{s_{_{NN}}}$=5.02 TeV, which have indicated strong anisotropic long-range angular distributions hadron pairs. origin these anisotropies is currently unknown. Various competing explanations include...
Transverse momentum spectra of electrons (${p}_{T}^{e}$) from semileptonic weak decays heavy-flavor mesons in the range $0.3<{p}_{T}^{e}<9.0$ GeV/$c$ have been measured at midrapidity ($|y|<0.35$) by PHENIX experiment Relativistic Heavy Ion Collider $p+p$ and $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{\mathrm{NN}}}=200$ GeV. In addition, azimuthal anisotropy parameter ${v}_{2}$ has for $0.3<{p}_{T}^{e}<5.0$ collisions. The substantial modification ${p}_{T}^{e}$ compared with as well...
The PHENIX experiment at the Relativistic Heavy Ion Collider has measured invariant differential cross section for production of ${K}_{S}^{0}$, $\ensuremath{\omega}$, ${\ensuremath{\eta}}^{\ensuremath{'}}$, and $\ensuremath{\phi}$ mesons in $p+p$ collisions $\sqrt{s}=200\text{ }\text{ }\mathrm{GeV}$. Measurements $\ensuremath{\omega}$ different decay channels give consistent results. New results are agreement with previously published data extend ${p}_{T}$ coverage. spectral shapes all...
The second Fourier component ${v}_{2}$ of the azimuthal anisotropy with respect to reaction plane is measured for direct photons at midrapidity and transverse momentum (${p}_{T}$) $1--12\text{ }\text{ }\mathrm{GeV}/c$ in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=200\text{ }\mathrm{GeV}$. Previous measurements this quantity hadrons ${p}_{T}<6\text{ indicate that medium behaves like a nearly perfect fluid, while ${p}_{T}>6\text{ reduced interpreted terms path-length dependence...
The momentum distribution of electrons from decays heavy flavor (charm and bottom) for midrapidity |y|<0.35 in p+p collisions at s=200 GeV has been measured by the PHENIX experiment BNL Relativistic Heavy Ion Collider over transverse range 0.3<pT<9 GeV/c. Two independent methods have used to determine heavy-flavor yields, results are good agreement with each other. A fixed-order-plus-next-to-leading-log perturbative QCD calculation agrees data within theoretical experimental uncertainties,...
Transverse momentum distributions and yields for ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}^{\ifmmode\pm\else\textpm\fi{}}$, $p$, $\mathrm{p\ifmmode \bar{}\else \={}\fi{}}$ in $p+p$ collisions at $\sqrt{s}$ $=$ 200 62.4 GeV midrapidity are measured by the PHENIX experiment Relativistic Heavy Ion Collider (RHIC). These data provide important baseline spectra comparisons with identified particle heavy ion RHIC. We present inverse slope parameter ${T}_{\mathrm{inv}}$, mean...
Heavy quarkonia are observed to be suppressed in relativistic heavy-ion collisions relative their production $p+p$ scaled by the number of binary collisions. In order determine if this suppression is related color screening these states produced medium, one needs account for other nuclear modifications including those cold matter. paper, we present new measurements from PHENIX 2007 data set $J/\ensuremath{\psi}$ yields at forward rapidity ($1.2<|y|<2.2$) $\text{Au}+\text{Au}$...
The PHENIX experiment presents results from the Relativistic Heavy Ion Collider 2005 run with polarized proton collisions at $\sqrt{s}=200\text{ }\text{ }\mathrm{GeV}$, for inclusive ${\ensuremath{\pi}}^{0}$ production midrapidity. Unpolarized cross section are given transverse momenta ${p}_{T}=0.5$ to $20\text{ }\mathrm{GeV}/c$, extending range of published data both lower and higher ${p}_{T}$. is described well ${p}_{T}<1\text{ }\mathrm{GeV}/c$ by an exponential in ${p}_{T}$, and,...
J/psi production in p+p collisions at square root s=200 GeV has been measured by the PHENIX experiment BNL Relativistic Heavy Ion Collider over a rapidity range of -2.2<y<2.2 and transverse momentum 0<pT<9 GeV/c. The size present data set allows detailed measurement both pT distributions is sufficient to constrain models. total cross section times branching ratio Bll sigma pp J/psi=178+/-3stat+/-53sys+/-18norm nb.
We present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers central d+Au minimum bias p+p collisions at √sNN=200 GeV. The hadron is measured midrapidity |η|<0.35, the large rapidity (−3.7<η<−3.1, Au-going direction). An enhanced near-side correlation across |Δη|>2.75 observed collisions. Using event plane method applied to distribution, we extract anisotropy strength v2 for inclusive up pT=4.5 GeV/c. also measurement of identified π±...
We present the first measurement of elliptic (v2) and triangular (v3) flow in high-multiplicity 3He+Au collisions at √sNN=200 GeV. Two-particle correlations, where particles have a large separation pseudorapidity, are compared p+p indicate that collective effects dominate second third Fourier components for correlations observed system. The behavior is quantified terms v2 v3 anisotropy coefficients measured with respect to their corresponding event planes. values comparable those previously...
Direct photons produced in relativistic heavy-ion collisions allow access to the state of matter during collision, because they do not experience strong interaction and can escape from fireball without scattering. New data PHENIX experiment at RHIC show that as a function impact parameter yield direct increases much more rapidly than particle production, which provides new evidence for emission system when it was most hot dense.
The PHENIX experiment has measured the production of ${\ensuremath{\pi}}^{0}$s in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{\mathit{NN}}}$ $=$ 200 GeV. new data offer a fourfold increase recorded luminosity, providing higher precision and larger reach transverse momentum, ${p}_{T}$, to 20 GeV/$c$. ratio $\ensuremath{\eta}/{\ensuremath{\pi}}^{0}$ is $0.46\ifmmode\pm\else\textpm\fi{}0.01(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.05(\mathrm{syst})$, constant with ${p}_{T}$ collision...
The transverse momentum (${p}_{T}$) spectra and ratios of identified charged hadrons (${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}^{\ifmmode\pm\else\textpm\fi{}}$, $p$, $\overline{p}$) produced in $\sqrt{{s}_{{}_{NN}}}=200$ GeV $\mathrm{Au}+\mathrm{Au}$ $d+\text{Au}$ collisions are reported five different centrality classes for each collision species. measurements pions protons up to ${p}_{T}=6$ GeV/$c$ (5 GeV/$c$), the kaons ${p}_{T}=4$ (3.5 GeV/$c$) ($d+\text{Au}$) collisions....