Eur. Phys. J. C (2008) 56: 493-510
https://doi.org/10.1140/epjc/s10052-008-0671-x

Regular Article - Theoretical Physics

The thermal production of strange and non-strange hadrons in e ⁺ e ⁻ collisions

¹ Dipartimento di Fisica, Università di Firenze, and INFN Sezione di Firenze, 50019, Sesto Fiorentino (Firenze), Italy
² Dipartimento di Fisica, Università di Catania, and INFN Sezione di Catania, 95123, Catania, Italy
³ INFN Sezione di Firenze, 50019, Sesto Fiorentino (Firenze), Italy
⁴ Fakultät für Physik, Universität Bielefeld, 33615, Bielefeld, Germany

^* e-mail: satz@physik.uni-bielefeld.de

Received: 16 May 2008
Published online: 5 August 2008

Abstract

The thermal multihadron production observed in different high energy collisions poses two basic problems. (1) Why do even elementary collisions with comparatively few secondaries (e ⁺ e ⁻ annihilation) show thermal behavior? (2) Why is there in such interactions a suppression of strange particle production? We show that the recently proposed mechanism of thermal hadron production through Hawking–Unruh radiation can naturally account for both. The event horizon of color confinement leads to thermal behavior, but the resulting temperature depends on the strange quark content of the produced hadrons, causing a deviation from full equilibrium and hence a suppression of strange particle production. We apply the resulting formalism to multihadron production in e ⁺ e ⁻ annihilation over a wide energy range and make a comprehensive analysis of the data in the conventional statistical hadronization model and the modified Hawking–Unruh formulation. We show that this formulation provides a very good description of the measured hadronic abundances, fully determined in terms of the string tension and the bare strange quark mass; it contains no adjustable parameters.