Spinodal Decomposition in High Temperature Gauge Theories

After a rapid increase in temperature across the deconfinement temperature $$, pure gauge theories exhibit unstable long wavelength fluctuations in the approach to equilibrium. This phenomenon is analogous to spinodal decomposition observed in condensed matter physics, and also seen in models of disordered chiral condensate formation. At high temperature, the unstable modes occur only in the range $0\leq k$ $\leq k_{c}$, where $k_{c}$ is on the order of the Debye screening mass $m_D$. Equilibration always occurs via spinodal decomposition for $SU(2)$at temperatures $T>T_{d}$ and for SU(3) for $T\gg T_{d}$. For SU(3) at temperatures $T\gtrsim T_{d}$, nucleation may replace spinodal decomposition as the dominant equilibration mechanism. Monte Carlo simulations of SU(2) lattice gauge theory exhibit the predicted phenomena. The observed value of $k_c$ is in reasonable agreement with a value predicted from previous lattice measurements of $m_D$.