The Legacy of Rolf Hagedorn: Statistical Bootstrap and Ultimate Temperature

TL;DR

This paper reviews Rolf Hagedorn's pioneering work on the statistical bootstrap model, which predicts a limiting temperature for strongly interacting matter based on self-similar particle mass distributions, influencing high energy physics.

Contribution

It highlights the conceptual foundation of Hagedorn's approach and its impact on understanding particle states and critical phenomena in high energy physics.

Findings

Hagedorn's model predicts an exponential growth in particle states.

Introduction of the concept of a limiting temperature in hadronic matter.

Application of the model to various areas in high energy physics.

Abstract

In the latter half of the last century, it became evident that there exists an ever increasing number of different states of the so-called elementary particles. The usual reductionist approach to this problem was to search for a simpler infrastructure, culminating in the formulation of the quark model and quantum chromodynamics. In a complementary, completely novel approach, Hagedorn suggested that the mass distribution of the produced particles follows a self-similar composition pattern, predicting an unbounded number of states of increasing mass. He then concluded that such a growth would lead to a limiting temperature for strongly interacting matter. We discuss the conceptual basis for this approach, its relation to critical behavior, and its subsequent applications in different areas of high energy physics.