Melting Hadrons, Boiling Quarks

TL;DR

This paper reviews the understanding of hot hadronic matter and quark-gluon plasma, discussing properties, phase transitions, experimental signatures, and theoretical models related to the Hagedorn temperature.

Contribution

It provides a comprehensive overview of the properties and signatures of quark-gluon plasma, including new predictions about hadron matter and QGP formation in heavy ion collisions.

Findings

Strangeness and strange antibaryons as signatures of QGP

Predictions of QGP formation in relativistic heavy ion collisions

Historical context of QGP discovery

Abstract

In the context of the Hagedorn temperature half-centenary I describe our understanding of the hot phases of hadronic matter both below and above the Hagedorn temperature. The first part of the review addresses many frequently posed questions about properties of hadronic matter in different phases, phase transition and the exploration of quark-gluon plasma (QGP). The historical context of the discovery of QGP is shown and the role of strangeness and strange antibaryon signature of QGP illustrated. In the second part I discuss the corresponding theoretical ideas and show how experimental results can be used to describe the properties of QGP at hadronization. The material of this review is complemented by two early and unpublished reports containing the prediction of the different forms of hadron matter, and of the formation of QGP in relativistic heavy ion collisions, including the discussion of strangeness, and in particular strange antibaryon signature of QGP.