Chinese Acad Sci, Shanghai Inst Nucl Res, Shanghai 201800, Peoples R China
; Chinese Acad Sci, Ctr Theoret Nucl Phys, Natl Lab heavy Ion Accelerator, Inst Modern Phys, Lanzhou 730000, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
We have studied dilepton production during the chemical equilibration of baryon-rich quark-gloun matter, and found that due to the slowing down of the cooling rate and the high initial temperature of the quark-gloun matter(QGM) produced at RHIC energies, the quark phase contribution to dileptons with intermediate masses is significantly heightened, thus, the enhancement of dileptons with intermediate masses should be an signal for the QGM formation. Since this enhancement can compensate the dilepton suppression caused by increasing the initial chemical potential, therefore, the dilopton suppression may not be a signal for the quark-gloun matter formation.