Taking account of elastic gg→gg and bremsstrahlung gg↔ggg processes, as well as quark elastic scattering, we calculated the shear viscous coefficient of a chemically equilibrating quark-gluon plasma at finite baryon density. We found that the inelastic bremsstrahlung processes make the shear viscosity remarkably lower, and the ratio of shear viscosity to entropy density η/s increases with increasing initial quark chemical potential. Considering the effect of shear viscosity the evolution of the QGP system was investigated. We found that the evolution of the system becomes slower owing to viscosity compared to the one in the ideal case, and the inelastic bremsstrahlung processes make the slower rate of the system not as much as in our previous calculations.

We have studied the evolution and dilepton production of a chemically equilibrating quark-gluon system at finite baryon density. We found that due to the increase of the quark phase lifetime with increasing initial quark chemical potential and other factors, such as, higher initial temperature, larger gluon density, and gluon fusion or quark annihilation cross section, thermal charmed quarks provide a dominant contribution to the dilepton yield. This results in a significant enhancement of intermediate mass dilepton production.

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: qq→ll, qq→gll, Compton-like scattering (qg→qll,qg→qll), gluon fusion gḡ→cc, annihilation qq→cc 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.