Unruh thermalization, gluon condensation and freeze-out

Abstract

The deconfinement transition and the hadronization mechanism at high energy are related to the quark-antiquark string breaking and the corresponding temperature depends on the string tension $\sigma$. In the Unruh scheme of hadron production it turns out $T=\sqrt{\sigma /2\pi }$, with $\sigma \simeq \text{E}$, the vacuum energy density. In heavy ion collisions at lower energy, i.e. large baryonchemical potential, ${\mu }_B$, the dynamics is dominated by Fermi statistics and baryon repulsion. However one can still consider $\text{E}$ as the relevant physical scale and its evaluation as a function of the baryon density, in a nuclear matter approach, gives dynamical information on the ${\mu }_B$ dependence of the hadronization temperature and on the value of the critical end point in the $T-{\mu }_B$ plane.

Comments: 8 pages, 6 figures, typos corrections and changes in the figures. In press in PRD