Magnetic flux loop in high-energy heavy-ion collisions

TL;DR

This paper investigates magnetic flux loops in high-energy heavy-ion collisions, revealing area law behavior for large loops, estimating magnetic string tension, and analyzing early-time gluon propagator corrections in strong magnetic fields.

Contribution

It introduces the behavior of magnetic flux loops in heavy-ion collisions, quantifies magnetic string tension, and studies early-time gluon propagator modifications in strong magnetic backgrounds.

Findings

Loops larger than ~2/Q_s^2 follow area law behavior.

Magnetic string tension estimated as sigma_M = 0.12 Q_s^2.

Small loops also satisfy area law at t ~ 1/Q_s.

Abstract

We consider the expectation value of a magnetic flux loop in the immediate forward light cone of collisions of heavy nuclei at high energies. Such collisions are characterized by a non-linear scale Q_s where color fields become strong. We find that loops of area greater than ~2/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 = 0.12 Q_s^2. By the time t ~ 1/Q_s even small loops satisfy an area law. We describe corrections to the propagator of semi-hard gluons at very early times in the background of fluctuating magnetic fields.