CCAST, World Lab, Beijing 100080, Peoples R China
; Chinese Acad Sci, Shanghai Inst Nucl Res, Shanghai 201800, Peoples R China
; Chinese Acad Sci, Inst Modern Phys, Res Ctr Nucl Theory, Natl Lab Heavy Ion Accelerator, Lanzhou 730000, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
We have studied the evolution and dilepton production of a chemically equilibrating quark-gluon plasma considering finite baryon density based on Juttner distribution of partons, and found that due to the increasing of the quark phase life-time with increasing initial quark chemical potential, high initial temperature, large gluon density of the system as well as large gluon fusion gg --> c (c) over bar cross section in the intermediate mass region, quark-antiquark annihilation q (q) over bar --> l (l) over bar, especially, thermal charmed quarks from the gluon fusion gg --> c (c) over bar and quark-antiquark annihilation q (q) over bar --> c (c) over bar provide a dominant contribution to dileptons, resulting in a significant enhancement of intermediate mass dileptons. (C) 2003 Elsevier B.V. All rights reserved.