Viscosity and dilepton production of a chemically equilibrating quark-gluon plasma at finite baryon density

TL;DR

This paper investigates how shear viscosity affects the evolution of a chemically equilibrating quark-gluon plasma at finite baryon density and calculates the resulting dilepton production, highlighting the importance of various scattering processes.

Contribution

It provides a comprehensive calculation of dilepton yields considering shear viscosity effects and finite baryon density, including multiple scattering processes and their impact on the plasma evolution.

Findings

Dilepton yield increases with initial quark chemical potential.

Viscosity extends the quark phase lifetime, raising dilepton production.

Multiple scattering processes significantly contribute to dilepton yields.

Abstract

By considering the effect of shear viscosity we have investigated the evolution of a chemically equilibrating quark-gluon plasma at finite baryon density. Based on the evolution of the system we have performed a complete calculation for the dilepton production from the following processes: $q\bar{q}{\to}l\bar{l}$, $q\bar{q}{\to}gl\bar{l}$, Compton-like scattering ($qg{\to}ql\bar{l}$, $\bar{q}g{\to}{\bar{q}}l\bar{l}$), gluon fusion $g\bar{g}{\to}c\bar{c}$, annihilation $q\bar{q}{\to}c\bar{c}$ as well as the multiple scattering of quarks. We have found that quark-antiquark annihilation, Compton-like scatterring, gluon fusion, and multiple scattering of quarks give important contributions. Moreover, we have also found that the dilepton yield is an increasing function of the initial quark chemical potential, and the increase of the quark phase lifetime because of the viscosity also obviously raises the dilepton yield.