The reach of collider energies in heavy-ion collisions has profoundly changed our understanding of QCD under extreme conditions. I review some these new developments and comment on the properties of the produced medium as extracted from experimental data, as well as the exciting new opportunities which will be open at the LHC. QCD is a theory with a very rich dynamical structure but difficult t...

We present the first measurement of reconstructed jets in ultra-relativistic heavy ion collisions. Utilizing the large coverage of the STAR Time Projection Chamber and Electromagnetic Calorimeter, we apply several modern jet reconstruction algorithms and background subtraction techniques and explore their systematic uncertainties in heavy ion events. The differential spectrum for inclusive jet ...

Can we study hot QCD using nuclear collisions? Can we learn about metallic hydrogen from the impact of comet Shoemaker-Levy 9 on Jupiter? The answer to both questions may surprise you! I summarize progress in relativistic heavy ion theory reported at DPF ‘94 in the parallel sessions. Lattice simulations of QCD demonstrate that matter at temperatures exceeding Tc ∼ 150 MeV is very different from...

The study of heavy ion interactions constitutes an important part of the experimental program outlined for the Large Hadron Collider under construction at CERN and expected to be operational by 2006. ALICE 1 is the single detector having the capabilities to explore at the same time most of the characteristics of high energy heavy ion interactions. Specific studies of jet quenching and quarkonia...

Due to their penetrating nature, dileptons are a valuable probe for the properties of the hot and/or dense medium created in relativistic heavy-ion collisions. Dilepton invariant-mass spectra provide direct access to the properties of the electromagnetic current-correlation function in strongly interacting matter. In this paper an overview is given of our current theoretical understanding of th...

One of the most promising probes to study deconfined matter created in high energy nuclear collisions is the energy loss of (heavy) quarks. It has been shown in experiments at the Relativistic Heavy Ion Collider that even charm and bottom quarks, despite their high mass, experience a remarkable medium suppression in the quark gluon plasma. In this exploratory investigation we study the energy l...