Shear and bulk viscosity of quark-gluon plasma with Gribov gluons and quasiparticle quarks

Abstract: In this study, we analyze the transport properties of the Quark-Gluon Plasma, focusing on bulk ($\zeta$) and shear ($\eta$) viscosities at vanishing chemical potential. To describe the QGP, we employ a quasiparticle model for quarks along with Gribov's prescription for gluons, which effectively captures non-perturbative dynamics. The Gribov parameter $\gamma_G$ and the dynamical mass $m_g$ are obtained by solving the one-loop gap equation in the $\overline{\text{MS}}$ renormalization scheme and further using lattice QCD data for the equation of state (EoS) of pure gluonic matter. The interaction between quarks and gluons is reflected in the quark quasi-mass $m_q$, again obtained using lattice EoS data for (2+1)-flavor QCD. Our primary goal is to invertigate the influence of quasi-quarks on the transport coefficients of QGP. Interestingly, we find a substantial decrease in the scaled transport coefficients with rising temperatures within the range ($1 \le T/T_c \le 3.5$).