Quark Matter 2015 - XXV International Conference on Ultrarelativistic Nucleus-Nucleus Collisions

Viscous corrections to anisotropic flow and transverse momentum spectra within a transport approach

29 Sept 2015, 16:30

2h

Exhibition space 3 & 4

Board: 0828

Poster Collective Dynamics Poster Session

Speaker

Salvatore Plumari (University of Catania (Italy))

Description

Viscous hydrodynamics is commonly used to model the evolution of the matter created in an ultra-relativistic heavy-ion collision. It provides a good description of transverse momentum spectra and anisotropic flow. These observables, however, cannot be consistently derived using viscous hydrodynamics alone, because they depend on the microscopic interactions at freeze-out. We derive the ideal hydrodynamic limit and the first-order viscous correction to anisotropic flow ( $v_2$ , $v_3$ and $v_4$ ) and momentum spectrum using a transport calculation [1]. We find that the linear response coefficient to the initial anisotropy, $v_n(p_T)/\epsilon_n$ , depends little on n in the ideal hydrodynamic limit. The viscous correction to the spectrum depends not only on the differential cross section, but also on the initial momentum distribution. This dependence is not captured by standard second-order viscous hydrodynamics. The viscous correction to anisotropic flow increases with $p_T$ in agreement with the recent analytical solutions of viscous hydrodynamic [2]. [1] S. Plumari, G. L. Guardo, V. Greco, J.Y. Ollitrault, Nucl.Phys. A 941 (2015) 87-96. [2] Y. Hatta, J. Noronha, G. Torrieri, B.W. Xiao, Phys.Rev. D 90 (2014) 7, 074026.