Onset of deconfinement in nucleus-nucleus collisions: Review for pedestrians and experts

TL;DR

This review discusses the evidence and theoretical understanding of the energy threshold for quark-gluon plasma formation in nucleus-nucleus collisions, highlighting experimental results from CERN SPS and their interpretation.

Contribution

It provides a comprehensive overview of the experimental and theoretical status of the onset of deconfinement, including recent results and open questions, accessible to both experts and non-experts.

Findings

Evidence for the energy threshold of quark-gluon plasma creation

Comparison of experimental results with statistical model predictions

Discussion of alternative interpretations and unresolved questions

Abstract

Evidence for the energy threshold of creating the quark-gluon plasma in nucleus-nucleus collisions, the so-called onset of deconfinement, has been found by the energy scan program of the NA49 experiment at the CERN SPS. In this paper we review the experimental and theoretical status of this phenomenon. First, the basic, qualitative ideas are presented for non-experts. Next, the latest experimental results are compared to a statistical model within which the onset of deconfinement and its signals had been predicted. Finally, alternative interpretations and open questions are discussed.