We consider the expectation value of a chromomagnetic flux loop in the immediate forward light cone of collisions of heavy nuclei at high energies. Such collisions are characterized by a nonlinear scale $Q_s$ where color fields become strong. We find that loops of area greater than $\sim 1.5/Q_s^2$ exhibit area-law behavior, which determines the scale of elementary flux excitations (“vortices”). We also estimate the magnetic string tension, ${\sigma }_M\simeq 0.12Q_s^2$. By the time $t\sim 1/Q_s$ even small loops satisfy area-law scaling. We describe corrections to the propagator of semihard particles at very early times in the background of fluctuating magnetic fields.

• Received 18 February 2013

DOI:https://doi.org/10.1103/PhysRevD.88.054016