PHQMD—A Microscopic Transport Approach for Heavy-Ion Collisions and Cluster Formation

We present the basic ideas and new results of the recently advanced transport approach called PHQMD (Parton-Hadron-Quantum Molecular Dynamics) to describe heavy-ion collisions and especially the cluster formation in these reactions. This n-body transport approach allows to address physical processes which cannot be addressed by transport approaches which calculate the time evolution of the one-body phase space density or the one-body Greens function. They include the formation of fragments, especially of hyper-fragments, as well as the study of fluctuations as a signal of a possible first-order phase transition which some models predict if the strongly interacting matter is compressed to a high baryon density. This approach is at the same time an extension of the QMD model, which has successfully been used to describe fragments and other observables in heavy-ion collisions at beam energies below 2 AGeV and the PHSD transport approach which is a microscopic covariant dynamical transport approach for the one-body Greens function which successfully described a multitude of single-particle observables in p+p, p+A and A+A collisions from lower SIS (\(E_{beam} = 1\ \)AGeV) to LHC energies (\(\sqrt{s} =\ 5.2 \ \)TeV). We present the model and discuss how the parametrization of nuclear potential interactions influences the prediction for different observables.