Gerd Röpke (University of Rostock & IFT)
Clusters and few-body correlations in hot and dense nuclear matter
A Green's function approach is used to investigate correlations and cluster formation of nucleons in nuclear matter at temperatures up to 100 MeV. This thermodynamic Green's function approach is applied to hadronic matter at subsaturation densities where light nuclei as well as continuum correlations determine the thermodynamic and transport properties, in particular phase transitions and neutrino transport. The quantum statistical approach is also applied to hadronization phenomena in the quark-gluon plasma, which occur at higher densities and temperatures. Clusters are described as quasiparticles, medium modifications owing to self-energy terms and Pauli-blocking effects are calculated. In particular, the role of unstable nuclei is investigated. The treatment of correlations and cluster formation is of interest to astrophysics, for example, the structure and temporal evolution of neutron stars. In laboratory experiments, properties of matter at extreme energy densities are investigated with heavy-ion collisions, e.g., at LHC. Medium modifications as well as nonequilibrium approaches are applied to explain the observed yields of light clusters.