Disoriented Chiral Condensates: A Dynamical Simulation in the (2+1)-Dimensional Gross-Neveu Model

Abstract

We simulate the formation and growth of disoriented chiral condensate (DCC) regions which follow the expansion of a high energy density region into the ``cold'' vacuum. The numerical study is based on the one-loop effective potential for the massive 2+1-dimensional Gross-Neveu model. We pay attention to the setting of the initial conditions and to determining which parameters are relevant for a strong amplification of the pion field. We find that the size of the ``hot'' source plays a significant role. For large enough source radii, we observe strong correlation phenomena, corresponding to the growth of large regions where the pion field oscillates along a given direction. We give our results in terms of the $\theta$ angle which defines the DCC disorientation, of the other $O(4)$ angles distributions, of the local ratios $R_a={\pi }_a^2/{\vec{\pi }}^2$ $(a=1,2,3)$, and of the energies associated with the fields at representative times.

Comments: 21 pages, standard LaTeX file. 11 Figures (not included) available upon request (hard copy or Postscript (10 Mb)) by e-mail to: pettini@sc2a.unige.ch or pettini@fi.infn.it