Article

Influence of a temperature-dependent shear viscosity on the azimuthal asymmetries of transverse momentum spectra in ultrarelativistic heavy-ion collisions

Physical Review C (Impact Factor: 3.88). 03/2012; 86(1). DOI: 10.1103/PhysRevC.86.014909
Source: arXiv

ABSTRACT We study the influence of a temperature-dependent shear viscosity over
entropy density ratio $\eta/s$, different shear relaxation times $\tau_\pi$, as
well as different initial conditions on the transverse momentum spectra of
charged hadrons and identified particles. We investigate the azimuthal flow
asymmetries as a function of both collision energy and centrality. The elliptic
flow coefficient turns out to be dominated by the hadronic viscosity at RHIC
energies. Only at higher collision energies the impact of the viscosity in the
QGP phase is visible in the flow asymmetries. Nevertheless, the shear viscosity
near the QCD transition region has the largest impact on the collective flow of
the system. We also find that the centrality dependence of the elliptic flow is
sensitive to the temperature dependence of $\eta/s$.

1 Follower
 · 
71 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: I will review the current status of describing spcetime evolution of the relativistic nuclear collisions with fluid dynamics, and of determining the transport coefficients of strongly interacting matter. The fluid dynamical models suggest that shear viscosity to entropy density ratio of the matter is small. However, there are still considerable challenges in determining the transport coefficients, and especially their temperature dependence is still poorly constrained.
    Nuclear Physics A 10/2014; 931. DOI:10.1016/j.nuclphysa.2014.09.100 · 2.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Anisotropic hydrodynamics is a non-perturbative reorganization of relativistic hydrodynamics that takes into account the large momentum-space anisotropies generated in ultrarelativistic heavy-ion collisions. As a result, it allows one to extend the regime of applicability of hydrodynamic treatments to situations that can be quite far from isotropic thermal equilibrium. In this paper, I review the material presented in a series of three introductory lectures. I review the derivation of ideal and second-order viscous hydrodynamics from kinetic theory. I then show how to extend the methods used to a system that can be highly anisotropic in local-rest-frame momenta. I close by discussing recent work on this topic and then present an outlook to the future.
    Acta Physica Polonica Series B 10/2014; 45(12). DOI:10.5506/APhysPolB.45.2355 · 1.00 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We compute the temporal evolution of the pressure anisotropy and bulk pressure of a massive gas using second-order viscous hydrodynamics and anisotropic hydrodynamics. We then compare our results with an exact solution of the Boltzmann equation for a massive gas in the relaxation time approximation. We demonstrate that, within second-order viscous hydrodynamics, the inclusion of the full set of kinetic coefficients, particularly the shear-bulk couplings, is necessary to properly describe the time evolution of the bulk pressure. We also compare the results of second-order hydrodynamics with those obtained using the anisotropic hydrodynamics approach. We find that anisotropic hydrodynamics and second-order viscous hydrodynamics including the shear-bulk couplings are both able to reproduce the exact evolution with comparable accuracy.
    Physical Review C 07/2014; 90(4). DOI:10.1103/PhysRevC.90.044905 · 3.88 Impact Factor

Full-text (2 Sources)

Download
10 Downloads
Available from
May 29, 2014