Enhanced dilepton radiation at RHIC

Recently, there is growing evidence that a new state of matter is formed in sNN=200GeV Au+Au collisions at RHIC: a strongly coupled Quark Gluon Plasma of partonic degrees of freedom which develops a collective motion. Dilepton spectra are not affected by strong interaction and can therefore probe the whole time evolution of the collision. Thus they may be sensitive to the onset of deconfinement, chiral symmetry restoration, as well as the production of thermal photons. The PHENIX experiment measured the production of e+e− pairs in p+p and Au+Au collisions at sNN=200GeV. An enhanced dilepton yield in the mass range 150