System size and shape dependences of collective flow fluctuations in relativistic nuclear collisions

Abstract

Quantum fluctuations plays an essential role in forming the collective flow of hadrons observed in relativistic heavy-ion collisions. Event-by-event fluctuations of the collective flow can arise from various sources, such as the fluctuations in the initial geometry, hydrodynamic expansion, hadronization, and hadronic evolution of the nuclear matter, while the exact contribution from each source is still an open question. Using a (3+1)-dimensional relativistic hydrodynamic model coupled to a Monte-Carlo Glauber initial condition, Cooper-Frye particlization and a hadronic transport model, we explore the system size and shape dependences of the collective flow fluctuations in Au+Au, Cu+Au, and O+O collisions at $\sqrt{s_{\mathrm{NN}}}=200$~GeV. The particle yields, mean transverse momenta, 2-particle and 4-particle cumulant elliptic flows ($v_2\{2\}$ and $v_2\{4\}$) from our calculation agree with the currently existing data from RHIC. Different centrality dependences of the flow fluctuations, quantified by the $v_2\{4\}/v_2\{2\}$ ratio, are found for different collision systems due to their different sizes and shapes. By comparing $v_2\{4\}/v_2\{2\}$ between different hadron species, and comparing $v_2\{4\}/v_2\{2\}$ to the initial state geometric fluctuations quantified by the cumulant eccentricity ratio ${\epsilon }_2\{4\}/{\epsilon }_2\{2\}$, we find that while the initial state fluctuations are the main source of the $v_2$ fluctuations in large collision systems, other sources like nonlinear hydrodynamic response, hadronization, and hadronic afterburner can significantly affect the $v_2$ fluctuations in small systems.

12 pages, 6 figures

References in corpus (33)

• Systematic Measurements of Identified Particle Spectra in pp, d+Au and Au+Au Collisions from STAR
• Scaling properties of azimuthal anisotropy in Au+Au and Cu+Cu collisions at sqrt(s_NN) = 200 GeV
• Multi-system Bayesian constraints on the transport coefficients of QCD matter
• Effects of initial flow velocity fluctuation in event-by-event (3+1)D hydrodynamics
• Translation of collision geometry fluctuations into momentum anisotropies in relativistic heavy-ion collisions
• Elliptic flow of identified hadrons in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Constraining the Eq. of State of Super-Hadronic Matter from Heavy-Ion Collisions
• Running the gamut of high energy nuclear collisions
• Directed flow in ultrarelativistic heavy-ion collisions
• A collision geometry-based 3D initial condition for relativistic heavy-ion collisions
• Evidence of quadrupole and octupole deformations in ${}^{96}$Zr+${}^{96}$Zr and ${}^{96}$Ru+${}^{96}$Ru collisions at ultra-relativistic energies
• Probing triaxial deformation of atomic nuclei in high-energy heavy ion collisions
• Thermally Fluctuating Second-Order Viscous Hydrodynamics and Heavy-Ion Collisions
• Multi-particle and charge-dependent azimuthal correlations in heavy-ion collisions at the Relativistic Heavy-Ion Collider
• (3+1)-D viscous hydrodynamics CLVisc at finite net baryon density: identified particle spectra, anisotropic flows and flow fluctuations across BES energies
• QCD Equation of State at Finite Chemical Potentials for Relativistic Nuclear Collisions
• Rapidity decorrelation of anisotropic flow caused by hydrodynamic fluctuations
• Anisotropic flow and flow fluctuations of identified hadrons in Pb$-$Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Revisiting Bayesian constraints on the transport coefficients of QCD
• Longitudinal distribution of initial energy density and directed flow of charged particles in relativistic heavy-ion collisions
• Modified equilibrium distributions for Cooper--Frye particlization
• Benchmarking a Non-Equilibrium Approach to Photon Emission in Relativistic Heavy-Ion Collisions
• Non-Gaussian fluctuation dynamics in relativistic fluids
• Collision-System and Beam-Energy Dependence of Anisotropic Flow Fluctuations
• Anisotropic flow in Cu+Au collisions at $\sqrt{s_{NN}}=200$ GeV
• Investigation of the elliptic flow fluctuations of the identified particles using the A Multi-Phase Transport model
• Nickel isotopes in stellar matter
• Effects of hydrodynamic and initial longitudinal fluctuations on rapidity decorrelation of collective flow
• Hydrodynamic fluctuations and ultra-central flow puzzle in heavy-ion collisions
• Hydrodynamic description of $D$ meson production in high-energy heavy-ion collisions
• Particle productions and anisotropic flows from the AMPT model for Cu+Au collisions at $\sqrt{s_{NN}}=200$ GeV
• Far From Equilibrium Hydrodynamics and the Beam Energy Scan
• Elliptic flow of strange and multi-strange hadrons in isobar collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV at RHIC