Bulk Viscosity Of Hot Dense Quark Matter In PNJL Model

The initial stage of the Relativistic heavy ion collisions corresponds a preequlibrium, nonequlibrium processes.Viscoscous phenomenon exists commonly in the transport processes of nonequilibrium systems.The relevant characteristic parameters are shear viscosity and bulk viscosity. AS we all know, there are quark confinement and asymptotic freedom in QCD. In the processes of chiral transition and deconfinement transition, bulk viscosity has anomalous properties. The ratio of bulk viscosity to entropy is large near the critical temperature in zero baryon density. People conjecture that the quark matter is not a perfect fluid near the phase transition. Viscosity coefficients affect the Elliptic flow parameter V2 in the high energy heavy-ion collisions. To discuss properties of QGP, it is important to study bulk viscosity. They are also important for the physics of compact stars.PNJL model is an effective theory of QCD. Using retarded current-current correlation function one can calculate transport coefficients. We use the spectral density in quantum field theory at finite temperature to extract the bulk viscosity of hot quark-matter at finite density from the Kubo formulae. We calculate the value of bulk viscosity in the P-NJL model. And we find the value of bulk viscosity has a peak near the chiral phase transition. The ratio of bulk viscosity to entropy is large near the critical point. Along with the increasing of temperature, bulk viscosity approach zero rapidly. The increasing of baryon density raises the bulk viscosity.In this thesis firstly we introduce the basics of quantum chromo-dynamics, the transport theory and the effective model. The second section is the theoretical analysis, numerical computation and results discussion of this thesis. Finally, there are summary and prospects for my work.