Effect of bulk viscosity on elliptic flow near the QCD phase transition

Abstract

In this work, we examine the effect of bulk viscosity on elliptic flow, taking into account the critical behavior of the equation of state and transport coefficients near the QCD phase transition. We found that the p T dependence of v 2 is quantitatively changed by the presence of the QCD phase transition. Within reasonable values of the transport coefficients, v 2 decreases by a factor of 15% at small p T values (<1 GeV). However, for larger values of p T (>2 GeV), the interplay between the velocity of sound and transport coefficient near the QCD phase transition enhances v 2 . We point out that Grad's 14-moment approximation cannot be applied for the calculation of the one-particle distribution function at the freeze-out. A. Memory function method in a hyperbolic coordinate systemAs is well known, the application of dissipative hydrodynamics in the relativistic regime requires some caution. Recently, it became clear that the instability of the hydrodynamic

Bulk viscosity for pion and nucleon thermal fluctuation in the hadron resonance gas model

“…These momentum distribution of Γ π and Γ N will be integrated out when we will estimate ζ π and ζ N from Eqs. (8) and (9) respectively. Let us come to the different loop contributions of pion and nucleon thermal width in bulk viscosity coefficient of hadronic matter.…”

“…[5] exposes the possibility of divergence of ζ near the transition temperature. In recent times, different phenomenological investigations [6][7][8][9][10][11][12][13][14][15][16][17][18] demonstrated that bulk viscosity can have a non-negligible effect on heavy ion observables, where the values of ζ/s in Ref. [18] is assumed to be quite large.…”

Dissipative hydrodynamics coupled to chiral fields

“…See also Refs. [90][91][92][93] for recent work on the reliability of Grad's ansatz. By performing viscous hydrodynamic simulations with different dependencies of δf on p T , the authors of Refs.…”

Quark polarization in a viscous quark-gluon plasma

“…Before discussing how the quark polarization evolves in a viscous QGP due to multiple scattering, we have to know how the QGP itself evolves through either transport model or viscous hydrodynamical model [9,10,[27][28][29][30][31], Moreover, we also have to know the initial profile of the longitudinal flow field. In the discussion in Sec.…”