QCD predicts that strongly interacting matter will undergo a transition from a state of hadronic constituents to a plasma of unbound quarks and gluons. We first survey the conceptual features of this transition and its description in finite temperature lattice QCD, before we address its experimental investigation through high energy nucleus-nucleus… (More)
The deconfinement transition in SU(2) gauge theory and the magnetization transition in the Ising model belong to the same universality class. The critical behaviour of the Ising model can be characterized either as spontaneous breaking of the Z 2 symmetry of spin states or as percolation of appropriately defined spin clusters. We show that decon-finement in… (More)
Load balancing in large parallel systems with distributed memory is a diicult task often innuencing the overall eeciency of applications substantially. A number of eecient distributed load balancing strategies have been developed in the recent years. Although they are currently not generally available as part of parallel operating systems, it is often not… (More)
Finite temperature lattice QCD indicates that the charmonium ground state J/ψ can survive in a quark-gluon plasma up to 1.5 T c or more, while the excited states χ c and ψ ′ are dissociated just above T c. We assume that the χ c suffers the same form of suppression as that observed for the ψ ′ in SPS experiments, and that the directly produced J/ψ is… (More)
About 40-50 % of the quarkonium ground states J/ψ(1S) and Υ(1S) produced in hadronic collisions originate from the decay of higher excitations. In a hot medium, these higher states are dissociated at lower temperatures than the more tightly bound ground states, leading to a sequential suppression pattern. Using new finite temperature lattice results, we… (More)
Using percolation theory, we derive a conceptual definition of deconfinement in terms of cluster formation. The result is readily applicable to infinite volume equilibrium matter as well as to finite size pre-equilibrium systems in nuclear collisions.
At high temperatures or densities, hadronic matter shows different forms of critical behaviour: colour deconfinement, chiral symmetry restoration, and diquark condensation. I first discuss the conceptual basis of these phenomena and then consider the description of colour deconfinement in terms of symmetry breaking, through colour screening and as… (More)
The paramagnetic-ferromagnetic transition in the Ising model can be described as percolation of suitably defined clusters. We have tried to extend such picture to the confinement-deconfinement transition of SU (2) pure gauge theory, which is in the same universality class of the Ising model. The cluster definition is derived by approximating SU (2) by means… (More)