We discuss recent experimental results in the field of ultra-relativistic nuclear collisions. The emerging “picture” is a collectively expanding, initially hot and dense fireball in which strangenessand low-mass di-lepton pair production are enhanced and J/Ψ production is suppressed compared to expectations from nucleon-nucleon collisions. It is argued that, taken together, these data provide c...

We first review the production and the possible chemical equilibration of strange particles at CERN-SPS energies within a microscopic hadronic transport calculation. It is shown in particular that the strange quarks are produced initially via string excitations in the primary, secondary and ternary interactions. We then further elaborate on a recent idea of antihyperon production by multi-meson...

The theory of confinement and deconfinement is discussed as based on the properties of the QCD vacuum. The latter are described by field correlators of colour-electric and colour-magnetic fields in the vacuum, which can be calculated analytically and on the lattice. As a result one obtains a self-consistent theory of the confined region in the (µ, T) plane with realistic hadron properties. At t...

We study dilepton production from a thermally equilibrating quark-gluon plasma expected to be formed in ultra relativistic heavy-ion collisions. The pre-equilibrium dynamics of quark-gluon plasma is studied within the color flux-tube model by solving non-abelian relativistic transport equations. This dilepton rate crucially depends on the collision time of the plasma. The results are compared w...