Physics of strong electromagnetic fields in relativistic heavy-ion collisions

TL;DR

Relativistic heavy-ion collisions produce transient $B$-fields up to $10^{18}-10^{19}$ Gauss that couple to QGP and electromagnetic processes. The paper surveys theoretical frameworks—vacuum polarization, Landau-level quantization, relativistic MHD, and spin-augmented MHD—demonstrating how strong fields modify hard probes (photons, dileptons, heavy quarks) and drive anomalous transport in the hydrodynamic regime. Key findings include polarization-dependent photon dispersion, vacuum birefringence/dichroism, field-induced heavy-quark diffusion modifications, and magnetovortical transport with orbital angular momentum reversing prior spin-only predictions, expressed as $j^0 = -\frac{C_A}{2}\boldsymbol{\omega}\cdot\boldsymbol{B}$ with $C_A = \frac{e^2}{2\pi^2}$. The work highlights interdisciplinary connections and underscores the need for dynamic-field simulations and targeted experiments to fully exploit strong-field QCD phenomena.

Abstract

I discuss several roles of the strong electromagnetic fields created by relativistic heavy-ion collisions. These phenomena call for theoretical and experimental developments to understand dynamics of quark-gluon plasma (QGP) as well as purely electromagnetic processes in the ultraperipheral collisions.