Toward the Limits of Matter: Ultra-relativistic nuclear collisions at CERN

TL;DR

This paper reviews three decades of research at CERN on ultra-relativistic nuclear collisions, exploring the QCD phase transition from hadronic matter to quark-gluon plasma, and highlights its significance in modern nuclear physics.

Contribution

It provides a comprehensive overview of experimental progress and discoveries in ultra-relativistic heavy ion collisions at CERN over 30 years.

Findings

Evidence for quark-gluon plasma formation

Observation of the QCD phase transition

Development of experimental techniques for high-energy nuclear collisions

Abstract

Strongly interacting matter as described by the thermodynamics of QCD undergoes a phase transition, from a low temperature hadronic medium to a high temperature quark-gluon plasma state. In the early universe this transition occurred during the early microsecond era. It can be investigated in the laboratory, in collisions of nuclei at relativistic energy, which create "fireballs" of sufficient energy density to cross the QCD Phase boundary. We describe 3 decades of work at CERN, devoted to the study of the QCD plasma and the phase transition. From modest beginnings at the SPS, ultra-relativistic heavy ion physics has evolved today into a central pillar of contemporary nuclear physics and forms a significant part of the LHC program.