Di-lepton production in heavy-ion collisions and the QCD phase diagram

摘要

We reproduce di-electron spectra in the region of 0 < me+e? < 4GeV in both minimum bias and central Au+Au collisions at p√NN = 200 GeV measured by the STAR experiment. A cocktail simulation, incorporating STAR acceptance and detector responses, is able to describe the ”enhancement” of the low mass region by including an in-medium modification of vector mesons and a thermal di-lepton calculation. We also predict the di-lepton mass spectra in RHIC lower energies via an extrapolation method. The evolution of Di-lepton mass spectra, effective temperature, and possible medium modifications versus colliding energies are studied to explore the QCD phase diagram.