Comparison of results from a (2+1)-D relativistic viscous hydrodynamic model to elliptic and hexadecapole flow of charged hadrons measured in Au-Au collisions atsNN=200GeV

Abstract

Simulated results from a 2+1D relativistic viscous hydrodynamic model have been compared to the experimental data on the centrality dependence of invariant yield, elliptic flow (v2), and hexadecapole flow (v4) as a function of transverse momentum (pT ) of charged hadrons in Au-Au collisions at √ sNN = 200 GeV. Results from two types of initial transverse energy density profile, one based on the Glauber model and other based on Color-Glass-Condensate (CGC) are presented. We observe no difference in the simulated results on the invariant yield of charged hadrons for the calculations with different initial conditions. The comparison to the experimental data on invariant yield of charged hadrons supports a shear viscosity to entropy density ratio (η/s) between 0 to 0.12 for the 0-10% to 40-50% collision centralities. The simulated v2(pT ) is found to be higher for a fluid with CGC based initial condition compared to Glauber based initial condition for a given collision centrality. Consequently the Glauber based calculations when compared to the experimental data requires a lower value of η/s relative to CGC based calculations. In addition, a centrality dependence of the estimated η/s is observed from the v2(pT ) study. The v4(pT ) for the collision centralities 0-10% to 40-50% supports a η/s value between 0 -0.08 for a CGC based initial condition. While simulated results using the Glauber based initial condition for the ideal fluid evolution under estimates the v4(pT ) for collision centralities 0-10% to 30-40%.

Generalized planar black holes and the holography of hydrodynamic shear

“…However, it has recently come to be appreciated that, in non-central ("peripheral") collisions, the QGP is also subjected to an extremely intense shearing motion, because of the transverse non-uniformity of the colliding nuclei [11][12][13]. The large vorticity thus generated [14][15][16][17][18] may prove to have observable consequences, through quark polarization, and it may be important for forthcoming attempts to simulate peripheral collisions using holography [19].…”

Shear viscosity of a pion gas resulting fromρππandσππinteractions

“…To explain the elliptic flow parameter v 2 extracted from data collected at the Relativistic Heavy Ion Collider (RHIC) [1][2][3][4][5][6][7], hydrodynamical calculations [8][9][10][11][12] as well as some transport calculations [13][14][15][16] suggest that the matter produced in the collisions is likely to have a very small ratio of shear viscosity to entropy density η/s. Recent studies [17][18][19][20][21][22] have shown that η/s may reach a minimum in the vicinity of a phase transition-for earlier studies, see, e.g., Ref.…”

Viscous Hydrodynamic Model for Relativistic Heavy Ion Collisions

“…One can use a Gaussian distribution for ( ). Transverse energy distribution ( , ) can be conveniently parameterised in a Glauber model [17] or in color glass condensate (CGC) model [46][47][48]. I briefly discuss the Glauber and CGC initial conditions.…”

“…In Figure 9, viscous hydrodynamic simulation results [48] for transverse momentum spectra in √ = 200 GeV Au+Au collisions are compared with the PHENIX experiment. Glauber model initial condition was used for these simulations.…”