Transport Coefficient to Trace Anomaly in the Clustering of Color Sources Approach

Abstract

From our previously obtained shear viscosity to entropy density ratio ($\eta /s$) in the framework of clustering of color sources (Color String Percolation Model: CSPM), we calculate the jet quenching parameter $\hat{q}$ and trace anomaly $\Delta =(\epsilon -3p)/T^4$ as a function of temperature. It is shown that the scaled $\hat{q}/T^3$ is in agreement with the recent JET Collaboration estimates. The inverse of $\eta /s$ is found to represent $\Delta$. The results for $\Delta$ are in excellent agreement with Lattice Quantum Chromo Dynamics (LQCD) simulations. From the trace anomaly and energy density $ϵ$, the equation of state is obtained as a function of temperature and compared with LQCD simulations. It is possible that there is a direct connection between the $\eta /s$ and $\Delta$. Thus the estimate of transport coefficient $\eta /s$ provides $\hat{q}$ and $\Delta$ as a function of temperature. Both $\Delta$ and $\eta /s$ describe the transition from a strongly coupled QGP to a weakly coupled QGP.

Comments: 5 pages, 4 figures, Accepted for publication in Phys. Rev. C. arXiv admin note: text overlap with arXiv:1501.01524