Workgroup Carsten Greiner
Prof. Dr. Carsten Greiner
Theoretical nuclear and hadron physics
The physics of relativistic heavy ion collisions is a very active field of sub-nuclear physics. The investigation of central nucleus-nucleus collisions at relativistic energies aims at the understanding of the nuclear matter's properties under extreme conditions of temperature and density. Such conditions have existed in nature for some microseconds after the Big Bang and are assumed still to be found in neutron stars.
Of fundamental interest is the investigation of the interactions between various hadronic particles and their substructures - the quarks and gluons. In this way we gain insights into the nature of the strong interaction, which is described by quantum chromodynamics (QCD) in such an exited many-body system. A basic aspect is the possible formation of a deconfined state, the so called quark gluon plasma (QGP), in relativistic heavy-ion collisions.
The examination of the QGP is essential for a better understanding of the development of the early universe (the first few microseconds after the big bang).
In our group we are using relativistic transport models and non-equilibrium quantum field theory to describe the dynamics of the strongly interacting matter created in ultra-relativistic heavy-ion collisions, as investigated in experiments at GSI, RHIC, CERN, and in the future at FAIR and NICA.
With the parton-cascade simulation BAMPS (Boltzmann Approach to Multi-Parton Scattering) the Boltzmann Equation is solved for quarks and gluons based on cross sections from perturbative QCD, including 2<->3 in addition to the usual 2->2 scattering processes. Its application ranges from the description of flow parameters of the medium (RAA and v2 of partons), strangeness production to the study of heavy-quark diffusion.
Another focus of our interest is the investigation of the dynamics of the chiral phase transition of strongly interacting matter, applying non-equilibrium quantum-field theoretical models to derive quantum-transport equations.