Phenomenology of photon and dilepton production in relativistic nuclear collisions

We discuss the latest theoretical results on direct photon and dilepton production from relativistic heavy-ion collisions. While the dilepton spectra at low invariant mass show in-medium effects like collisional broadening of the vector meson spectral functions, the dilepton yield at high invariant masses (above 1.1 GeV) is dominated by QGP contributions for central heavy-ion collisions at relativistic energies. The present status of the photon v(2) "puzzle" - a large elliptic flow v2 of the direct photons experimentally observed at RHIC and LHC - energies is also addressed. The role of hadronic and partonic sources for the photon spectra and v(2) is considered as well as the possibility to subtract the QGP signal from the experimental observables. (C) 2014 Elsevier B.V. All rights reserved.