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

TL;DR

This paper links shear viscosity, jet quenching, and trace anomaly in the quark-gluon plasma using the clustering of color sources model, showing agreement with lattice QCD and experimental data, and explores the transition between strongly and weakly coupled QGP.

Contribution

It introduces a method to calculate jet quenching and trace anomaly from shear viscosity within the clustering of color sources framework, connecting these quantities to QGP properties.

Findings

Scaled jet quenching parameter matches experimental estimates.

Inverse shear viscosity to entropy density ratio correlates with trace anomaly.

Results agree with lattice QCD simulations for QGP properties.

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 $\Delta = (\varepsilon -3\it p)/T^{4}$ 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 $\epsilon$, 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.