Longitudinal distribution of initial energy density and directed flow of charged particles in relativistic heavy-ion collisions

Abstract

We study the origin of the directed flow of charged particles produced in relativistic heavy-ion collisions. Three different initial conditions, Boz$\dot{\text{e}}$k-Wyskiel, CCNU and Shen-Alzhrani, of energy density distributions are coupled to the (3+1)-dimensional viscous hydrodynamic model CLVisc, and their effects on the development of the anisotropic medium geometry, pressure gradient and radial flow are systematically compared. By comparing to experimental data at both RHIC and LHC, we find that the directed flow provides a unique constraint on the tilt of the initial medium profile in the plane spanned by the impact parameter and space-time rapidity. Within mid-rapidity, the counter-clockwise tilt is shown to be a crucial source of the positive/negative force by the pressure gradient along the impact parameter ($x$) direction at backward/forward rapidity, which drives a negative slope of the $x$ component of the medium flow velocity with respect to rapidity, and in the end the same feature of the charged particle directed flow.

12 pages, 10 figures, any comments or suggestions are welcome

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Cited by in corpus (13)

• The 3D structure of anisotropic flow in small collision systems at the Relativistic Heavy Ion Collider
• Probing initial baryon stopping and equation of state with rapidity-dependent directed flow of identified particles
• Probing the initial longitudinal density profile and electromagnetic field in ultrarelativistic heavy-ion collisions with heavy quarks
• Splitting of proton-antiproton directed flow in relativistic heavy-ion collisions
• Hyperon polarization and its relation with directed flow in high-energy nuclear collisions
• Directed flow and global polarization in Au+Au collisions across energies covered by the beam energy scan at RHIC
• Splitting of elliptic flow in a tilted fireball
• Anti-flow of Mesons in the High Baryon Density Region
• Non-extensive (3+1)-dimensional hydrodynamics for relativistic heavy-ion collisions
• Hydrodynamic simulations of directed flow for light hadrons in Au+Au and isobar collisions $\sqrt{s_{\text{NN}}}=$ 200 GeV
• System size and shape dependences of collective flow fluctuations in relativistic nuclear collisions
• Effect of hadronic interaction on the flow of $K^{\ast 0}$
• Interactions between heavy quarks and tilted QGP fireballs in 200 AGeV Au+Au collisions