Dissipative hydrodynamics coupled to chiral fields

Abstract

Using second-order dissipative hydrodynamics coupled self-consistently to the linear σ model we study the 2+1 dimensional evolution of the fireball created in Au+Au relativistic collisions. We analyze the influence of the dynamics of the chiral fields on the charged-hadron elliptic flow v2 and on the ratio v4/(v2)2 for a temperature-independent as well as for a temperature-dependent viscosity-to-entropy ratio η/s calculated from the linearized Boltzmann equation in the relaxation time approximation. We find that v2 is not very sensitive to the coupling of chiral sources to the hydrodynamic evolution, but the temperature dependence of η/s plays a much bigger role on this observable. On the other hand, the ratio v4/(v 2)2 turns out to be much more sensitive than v2 to both the coupling of the chiral sources and the temperature dependence of η/s. © 2011 American Physical Society.