corner
corner

Phys. Rev. Lett. 99, 242301 (2007) [4 pages]

Softening of the Equation of State of Matter at Large Densities and Temperatures: Chiral-Symmetry Restoration Versus Quark Deconfinement

Download: PDF (251 kB) Buy this article Export: BibTeX or EndNote (RIS)

Luca Bonanno and Alessandro Drago
Dipartimento di Fisica, Università di Ferrara and INFN, Sezione di Ferrara, 44100 Ferrara, Italy

Andrea Lavagno
Dipartimento di Fisica, Politecnico di Torino and INFN, Sezione di Torino, 10125 Torino, Italy

Received 27 April 2007; revised 20 September 2007; published 13 December 2007

We discuss two models in which a softening of the equation of state takes place due to the appearance of new degrees of freedom. The first is a hadronic model in which the softening is due to chiral symmetry restoration. In the second model the softening is associated with the formation of clusters of quarks in the mixed phase. We show that in the first case the bulk modulus is mainly dependent on the density, while in the mixed-phase model the bulk modulus strongly depends on the temperature and it is not vanishing due to the presence of two conserved charges, the baryon and the isospin one.

© 2007 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevLett.99.242301
DOI:
10.1103/PhysRevLett.99.242301
PACS:
21.65.+f, 12.39.Fe, 25.75.−q, 26.60.+c