1 Center for Theoretical Physics,
Massachusetts Institute of Technology,
Cambridge, MA 02139, USA
2 Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany
Received: 24 August 1999 / Published online: 17 February 2000 - © Springer-Verlag 2000
We investigate the chiral phase transition at high baryon number density within the linear quark meson model for two flavors. The method we employ is based on an exact renormalization group equation for the free energy. Truncated nonperturbative flow equations are derived at nonzero chemical potential and temperature. Whereas the renormalization group flow leads to spontaneous chiral symmetry breaking in vacuum, we find a chiral symmetry restoring first order transition at high density. Combined with previous investigations at nonzero temperature, the result implies the presence of a tricritical point with long-range correlations in the phase diagram.
Copyright Società Italiana di Fisica, Springer-Verlag 2000