Search

We investigate the properties of the QCD matter across the deconfinement phase transition in the scope of the parton-hadron string dynamics (PHSD) transport approach. We present here in particular the results on the electromagnetic radiation, i.e. photon and dilepton production, in relativistic heavy-ion collisions. By comparing our calculations for the heavy-ion collisions to the available data, we determine the relative importance of the various production sources and address the possible origin of the observed strong elliptic flow v2 of direct photons. We argue that the different centrality dependence of the hadronic and partonic sources for direct photon production in nucleus-nucleus collisions can be employed to shed some more light on the origin of the photon v2 "puzzle". While the dilepton spectra at low invariant mass show in-medium effects like an enhancement from multiple baryonic resonance formation or a 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 ultrarelativistic energies. This allows to have an independent view on the parton dynamics via their electromagnetic massive radiation. [ABSTRACT FROM AUTHOR]

We investigate meson electroproduction off complex nuclei in the kinematic regime of the HERMES experiment using a semi-classical transport model which is based on the Boltzmann­Uehling­Uhlenbeck (BUU) equation. We discuss coherence length and color transparency effects in exclusive ρ0 production as well as hadron formation and attenuation of charged pions, kaons, protons and anti-protons in deep inelastic lepton scattering off nuclei. [ABSTRACT FROM AUTHOR]