The Electro-Magnetic probes have been widely used to study the fundamental properties of hot, dense medium created in heavy ion collisions. Quarkonia through dileptonic decays have been an indicator of the de-confinement while the dileptons radiated from the hot, dense medium have been used to study Chiral Symmetry Restoration, the temperature, and lifetime of the medium.
I will briefly review a few interesting observables in heavy ion collisions and present most-recent STAR results on J/psi and dilepton production in the very low transverse momentum region (pT<0.2 GeV/c) in peripheral and mid-peripheral Au+Au collisions. The results seem to be consistent with the coherent photo-nuclear and two-photon processes, which have been widely studied in ultra-peripheral collisions. Physics implications and possible future measurements will be discussed.
In addition, I will try to make connections to future Electro-Magnetic measurements in e+A collisions.
