New formulation of leading order anisotropic hydrodynamics

Hot Quarks 2014: Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions

Tinti, Leonardo^1

Institute of Physics, Jan Kochanowski University, Kielce

PL-25406, Poland^1

关键词: Equilibrium limits;    Local equilibrium;    Massive particles;    Momentum spaces;    New approaches;    Relativistic hydrodynamics;    Symmetric flow;    Ultrarelativistic heavy ion collision;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/612/1/012061/pdf
DOI  :  10.1088/1742-6596/612/1/012061

来源: IOP

【 摘 要 】

Anisotropic hydrodynamics is a reorganization of the relativistic hydrodynamics expansion, with the leading order already containing substantial momentum-space anisotropies. The latter are a cause of concern in the traditional viscous hydrodynamics, since large momentum anisotropies generated in ultrarelativistic heavy-ion collisions are not consistent with the hypothesis of small deviations from an isotropic background, i.e., from the local equilibrium distribution. We discuss the leading order of the expansion, presenting a new formulation for the (1+1)- dimensional case, namely, for the longitudinally boost invariant and cylindrically symmetric flow. This new approach is consistent with the well established framework of Israel and Stewart in the close to equilibrium limit (where we expect viscous hydrodynamics to work well). If we consider the (0+1)-dimensional case, that is, transversally homogeneous and longitudinally boost invariant flow, the new form of anisotropic hydrodynamics leads to better agreement with known solutions of the Boltzmann equation than the previous formulations, especially when we consider massive particles.