Eur. Phys. J. Special Topics 155, 167-175 (2008)
https://doi.org/10.1140/epjst/e2008-00599-8

The origin of thermal hadron production

Fakultät für Physik, Universität Bielefeld, Bielefeld, Germany

Abstract

Multihadron production in high energy collisions, from e⁺e^- annihilation to heavy ion interactions, shows remarkable thermal behaviour, specified by a universal “Hagedorn” temperature. We argue that this hadronic radiation is formed by tunneling through the event horizon of colour confinement, i.e., that it is the QCD counterpart of Hawking-Unruh radiation from black holes. It is shown to be emitted at a universal temperature T_H ≃ (σ/2 π)^1/2, where σ denotes the string tension. Since the event horizon does not allow information transfer, the radiation is thermal “at birth”.