S. Afanasiev
A5073401967- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Computational Physics and Python Applications
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- Nuclear physics research studies
- Medical Imaging Techniques and Applications
- Nuclear reactor physics and engineering
- Astrophysics and Cosmic Phenomena
- Nuclear Physics and Applications
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
- Radiation Detection and Scintillator Technologies
- Distributed and Parallel Computing Systems
- Atomic and Subatomic Physics Research
- Particle Accelerators and Free-Electron Lasers
- International Science and Diplomacy
- Radiation Therapy and Dosimetry
- Hydraulic Fracturing and Reservoir Analysis
- Stochastic processes and financial applications
- Atomic and Molecular Physics
- Particle accelerators and beam dynamics
European Organization for Nuclear Research
2012-2025
Institute of High Energy Physics
2011-2024
University of Antwerp
2024
A. Alikhanyan National Laboratory
2023-2024
University of Notre Dame
2023-2024
Petersburg Nuclear Physics Institute
2023
Princeton University
2023
Joint Institute for Nuclear Research
2013-2022
Charles University
2018
Brookhaven National Laboratory
2018
The centrality dependence of transverse momentum distributions and yields for ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}},{K}^{\ifmmode\pm\else\textpm\fi{}},p$, $\overline{p}$ in $\text{Au}+\text{Au}$ collisions at $\sqrt{{s}_{NN}}=200\phantom{\rule{0.3em}{0ex}}\text{GeV}$ midrapidity are measured by the PHENIX experiment Relativistic Heavy Ion Collider. We observe a clear particle mass shapes spectra central below $\ensuremath{\sim}2\phantom{\rule{0.3em}{0ex}}\text{GeV}∕c$ ${p}_{T}$....
The anisotropy parameter (v(2)), the second harmonic of azimuthal particle distribution, has been measured with PHENIX detector in Au+Au collisions at sqrt[s(NN)]=200 GeV for identified and inclusive charged production central rapidities (|eta|<0.35) respect to reaction plane defined high (|eta|=3-4 ). We observe that v(2) mesons falls below (anti)baryons p(T)>2 GeV/c, marked contrast predictions a hydrodynamical model. A quark-coalescence model is also investigated.
Measurements of charged pion and kaon production in central Pb+Pb collisions at 40, 80, 158 A GeV are presented. These compared with data lower higher energies as well results from $p+p$ interactions. The mean multiplicity per wounded nucleon increases approximately linearly ${s}_{\mathrm{NN}}^{1/4}$ a change slope starting the region 15--40 GeV. suppression respect to interactions, observed low collision energies, enhancement high occurs about 40A nonmonotonic energy dependence ratio...
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...
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...
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 has measured midrapidity ([FORMULA: SEE TEXT]) transverse momentum spectra of electrons as a function centrality in Au+Au collisions at [FORMULA: TEXT]. Contributions from photon conversions and light hadron decays, mainly Dalitz decays pi0 eta mesons, were removed. resulting nonphotonic electron are primarily due to the semileptonic hadrons carrying heavy quarks. Nuclear modification factors determined by comparison p+p collisions. A significant suppression high pT is...
The first measurement of direct photons in Au + collisions at (square root)S(NN) = 200 GeV is presented. photon signal extracted as a function the collision centrality and compared to next-to-leading order perturbative quantum chromodynamics calculations. yield shown scale with number nucleon-nucleon for all centralities.
Inclusive transverse momentum spectra of $\ensuremath{\eta}$ mesons have been measured within ${p}_{T}=2--10\text{ }\text{ }\mathrm{GeV}/c$ at midrapidity by the PHENIX experiment in $\mathrm{Au}+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=200\text{ }\mathrm{GeV}$. In central yields are significantly suppressed compared to peripheral $\mathrm{Au}+\mathrm{Au}$, $d+\mathrm{Au}$, and $p+p$ scaled corresponding number nucleon-nucleon collisions. The magnitude, centrality, ${p}_{T}$ dependence...
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.
The dependence of transverse momentum spectra neutral pions and $\ensuremath{\eta}$ mesons with ${p}_{T}<16\text{ }\text{ }\mathrm{GeV}/c$ ${p}_{T}<12\text{ }\mathrm{GeV}/c$, respectively, on the centrality collision has been measured at midrapidity by PHENIX experiment BNL Relativistic Heavy Ion Collider (RHIC) in $d+\mathrm{Au}$ collisions $\sqrt{{s}_{NN}}=200\text{ }\mathrm{GeV}$. yields are compared to those $p+p$ same $\sqrt{{s}_{NN}}$ scaled number underlying nucleon-nucleon...
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.
Bose-Einstein correlations of identically charged pion pairs were measured by the PHENIX experiment at mid-rapidity in Au+Au collisions $\sqrt{s_{\rm NN}}$ = 200 GeV. The Bertsch-Pratt radius parameters determined as a function transverse momentum pair and centrality collision. Using \it{full} Coulomb correction, ratio $R_{\rm out}/R_{\rm side}$ is smaller than unity for $<k_{\rm T}>$ from 0.25 to 1.2 GeV/c all centralities. However, using recently developed partial correction methods, we...
Cross sections for midrapidity production of direct photons in p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are reported transverse momenta 3 < pT 16 GeV/c. Next-to-leading order perturbative QCD (pQCD) describes data well >5 GeV/c, where uncertainties measurement and theory comparable. We also report on effect requiring to be isolated from parton jet energy. The observed fraction is described by pQCD >7
The PHENIX experiment has measured midrapidity transverse momentum spectra (0.4<p(T)<4.0 GeV/c) of single electrons as a function centrality in Au+Au collisions at sqrt[s(NN)]=200 GeV. Contributions from photon conversions and Dalitz decays light neutral mesons are by introducing thin (1.7% X0) converter into the acceptance statistically removed. subtracted nonphotonic electron primarily due to semileptonic hadrons containing heavy quarks, mainly charm lower p(T). For all centralities,...
Differential elliptic flow (${v}_{2}$) for $\ensuremath{\phi}$ mesons and (anti)deuterons $(\overline{d})d$ is measured $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$. The ${v}_{2}$ follows the trend of lighter ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ ${K}^{\ifmmode\pm\else\textpm\fi{}}$ mesons, suggesting that ordinary hadrons interacting with standard hadronic cross sections are not primary driver development. values suggest additive...
Yields for J/psi production in Cu+Cu collisions at sqrt s_NN=200 GeV have been measured over the rapidity range |y|<2.2 and compared with results p+p Au+Au same energy. The data offer greatly improved precision existing small to intermediate numbers of participants, where quark-gluon plasma transition threshold is predicted lie. Cold nuclear matter estimates based on ad hoc fits d+Au describe up N_part approximately 50, corresponding a Bjorken energy density least 1.5 GeV/fm(3).
We present the first measurement of photoproduction J/ψ and two-photon production high-mass e+e− pairs in electromagnetic (or ultra-peripheral) nucleus–nucleus interactions, using Au + data at sNN=200 GeV. The events are tagged with forward neutrons emitted following Coulomb excitation one or both Au⋆ nuclei. event sample consists 28 me+e−>2 GeV/c2 zero like-sign background. measured cross sections midrapidity dσ/dy(J/ψ+Xn,y=0)=76±33(stat)±11(syst) μb...
The PHENIX experiment has measured the suppression of semi-inclusive single high-transverse-momentum ${\ensuremath{\pi}}^{0}$'s in Au+Au collisions at $\sqrt{{s}_{\mathit{NN}}}=200$ GeV. present understanding this is terms energy loss parent (fragmenting) parton a dense color-charge medium. We have performed quantitative comparison between various energy-loss models and our experimental data. statistical point-to-point uncorrelated as well correlated systematic uncertainties are taken into...
We have measured the azimuthal anisotropy of pi0's for 1 < pT 18 GeV/c Au+Au collisions at sqrt s_NN = 200 GeV. The observed shows a gradual decrease in 3 7 - 10 GeV/c, but remains positive beyond GeV/c. magnitude this is under-predicted, up to least by current perturbative QCD (pQCD) energy-loss model calculations. An estimate increase expected from initial-geometry modification due gluon saturation effects and fluctuations insufficient account discrepancy. Calculations which implement path...
We present measurements of $J/\ensuremath{\psi}$ yields in $d+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$ recorded by the PHENIX experiment and compare them with $p+p$ same energy per nucleon-nucleon collision. The cover a large kinematic range rapidity ($\ensuremath{-}2.2<y<2.4$) high statistical precision are compared two theoretical models: one nuclear shadowing combined final state breakup coherent gluon saturation effects. In order to remove model...