History of quark-gluon plasma evolution from photon interferometry

Two-photon intensity interferometry is used to probe the dynamics of quarks and gluons in a high-energy nucleus-nucleus collision. A (1+1)-dimensional expansion of the plasma according to Bjorken hydrodynamics as well as a (3+1)-dimensional expansion, both with a first-order phase transition, are considered. The correlation of high transverse-momentum photons is sensitive to the details of the space-time evolution of the high density QCD plasma. The so-called ''longitudinal'' and ''outward'' correlations are found to be dramatically affected by the transverse expansion of the system.