Open Access

Stefan Scherer, Steffen A. Bass, Mohamed Belkacem, Marcus Bleicher, Jörg Brachmann, Adrian Bogdan Dumitru, Christoph Ernst, Lars Gerland, Nils Hammon, Markus Hofmann, Jens Konopka, Ludwig Neise, Manuel Reiter, Stefan Schramm, Sven Soff, Christian Spieles, Henning Weber, Detlef Zschiesche, Joachim Maruhn, Horst Stöcker, Walter Greiner

• Nonequilibrium models (three-fluid hydrodynamics, UrQMD, and quark molecular dynamics) are used to discuss the uniqueness of often proposed experimental signatures for quark matter formation in relativistic heavy ion collisions from the SPS via RHIC to LHC. It is demonstrated that these models - although they do treat the most interesting early phase of the collisions quite differently (thermalizing QGP vs. coherent color fields with virtual particles) -- all yield a reasonable agreement with a large variety of the available heavy ion data. Hadron/hyperon yields, including J/Psi meson production/suppression, strange matter formation, dileptons, and directed flow (bounce-off and squeeze-out) are investigated. Observations of interesting phenomena in dense matter are reported. However, we emphasize the need for systematic future measurements to search for simultaneous irregularities in the excitation functions of several observables in order to come close to pinning the properties of hot, dense QCD matter from data. The role of future experiments with the STAR and ALICE detectors is pointed out.