Enhancement of the dielectron continuum in sqrt{s_NN} = 200 GeV Au+Au collisions

Understand

The PHENIX experiment has measured the dielectron continuum in sqrt{s_NN} = 200 GeV Au+Au collisions.

• In minimum bias collisions the dielectron yield in the mass range between 150 and 750 MeV/c^2 is enhanced by a factor of 3.4 +/- 0.2(stat.) +/- 1.3(syst.) +/- 0.7(model) compared to the expectation from our model of hadron decays.
• The integrated yield increases faster with the centrality of the collisions than the number of participating nucleons, suggesting emission from scattering processes in the hot and dense medium.
• The continuum yield between the masses of the phi and the J/psi mesons is consistent with expectations from correlated c-cbar production, though other mechanisms are not ruled out.