Eur. Phys. J. C (2009) 59: 67-73
https://doi.org/10.1140/epjc/s10052-008-0795-z

Regular Article - Theoretical Physics

The phase diagram of hadronic matter

¹ Dipartimento di Fisica, Università di Catania, and INFN Sezione di Catania, Catania, Italy
² Institute of Theoretical Physics, University of Wrocław, Wrocław, Poland
³ Technische Universität Darmstadt, Darmstadt, Germany
⁴ Fakultät für Physik, Universität Bielefeld, Bielefeld, Germany

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

Received: 22 August 2008
Published online: 29 November 2008

Abstract

We interpret the phase structure of hadronic matter in terms of the basic dynamical and geometrical features of hadrons. Increasing the density of constituents of finite spatial extension, by increasing the temperature T or the baryochemical potential μ, eventually “fills the box” and eliminates the physical vacuum. We determine the corresponding transition as a function of T and μ through percolation theory. At low baryon density, this means a fusion of overlapping mesonic bags to one large bag, while at high baryon density, hard-core repulsion restricts the spatial mobility of baryons. As a consequence, there are two distinct limiting regimes for hadronic matter. We compare our results to those from effective chiral model studies.