Electromagnetic probes in heavy-ion collisions

Messengers from the hot and dense phase

¹ Johann Wolfgang Goethe University Frankfurt, Institute for Theoretical Physics, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
² Frankfurt Institute of Advanced Studies, Ruth-Moufang-Str. 1, 60438 Frankfurt, Germany

^a e-mail: hees@fias.uni-frankfurt.de
^b e-mail: weil@fias.uni-frankfurt.de
^c e-mail: endres@th.physik.uni-frankfurt.de
^d e-mail: bleicher@th.physik.uni-frankfurt.de

Published online: 22 June 2015

Abstract

Due to their penetrating nature, electromagnetic probes, i.e., lepton-antilepton pairs (dileptons) and photons are unique tools to gain insight into the nature of the hot and dense medium of strongly-interacting particles created in relativistic heavy-ion collisions, including hints to the nature of the restoration of chiral symmetry of QCD. Of particular interest are the spectral properties of the electromagnetic current-correlation function of these particles within the dense and/or hot medium. The related theoretical investigations of the in-medium properties of the involved particles in both the partonic and hadronic part of the QCD phase diagram underline the importance of a proper understanding of the properties of various hadron resonances in the medium.