Highly occupied gauge theories in 2+1 dimensions: self-similar attractor

Understand

Motivated by the boost-invariant Glasma state in the initial stages in heavy-ion collisions, we perform classical-statistical simulations of SU(2) gauge theory in 2+1 dimensional space-time both with and without a scalar field in the adjoint representation.

• We show that irrespective of the details of the initial condition, the far-from-equilibrium evolution of these highly occupied systems approaches a unique universal attractor at high momenta that is the same for the gauge and scalar sectors.
• We extract the scaling exponents and the form of the distribution function close to this non-thermal fixed point.
• We find that the dynamics are governed by an energy cascade to higher momenta with scaling exponents $\alpha = 3\beta$ and $\beta = -1/5$.