Magnetic monopoles as probes of the global structure of the Standard Model

Abstract

The magnetic charges of monopoles arising in ultraviolet completions of the Standard Model are constrained by the global structure of the gauge group. After electroweak symmetry breaking, a subset of the ultraviolet monopoles carrying magnetic charges 3$g_D$ and $6g_D$ can survive as isolated, colour-neutral states in the infrared. We show that this selection rule follows from the interplay between the symmetry structure and the magnetic 1-form symmetry, and discuss how the relic abundance of such monopoles can be naturally suppressed by the symmetry breaking scale. We further demonstrate that such monopoles with Lorentz factor $\gamma\lesssim 10^4$ propagate through matter with ionisation energy loss profiles scaling as $g^2$ using CORSIKA Monte Carlo simulations.