Recasting Experimental Constraints on Relativistic Magnetic Monopoles

TL;DR

This paper refines constraints on relativistic magnetic monopoles by explicitly calculating their velocities based on cosmic magnetic field models, leading to updated flux limits across a broad mass range and exploring their potential as cosmic magnetic field probes.

Contribution

It introduces a method to determine monopole velocities from cosmic magnetic field data, improving the interpretation of experimental flux limits for various monopole masses.

Findings

Recast experimental flux limits as functions of monopole mass and velocity.

Derived new flux constraints for monopoles up to 10^{14} GeV.

Discussed monopoles as probes of intergalactic magnetic fields.

Abstract

Magnetic monopoles with masses up to $10^{14}$ GeV can be accelerated to relativistic velocities in Galactic and intergalactic magnetic fields. The cosmic flux of relativistic monopoles is constrained by various experiments, with the limits given as functions of the monopole velocity (Lorentz factor) at the detectors. The velocity, however, is usually treated as a free parameter due to the ambiguity in the computation of the acceleration before the monopoles arrive at Earth. We explicitly evaluate the velocity by exploiting recent studies on cosmic magnetic fields and the monopole acceleration therein, to recast experimental limits in terms of the mass of monopoles. By applying our method to various terrestrial experiments, including the Pierre Auger Observatory, IceCube, MACRO, and the upcoming Cherenkov Telescope Array Observatory, as well as to astrophysical constraints, we report limits on the flux of monopoles for a wide range of monopole masses. We also highlight the role of monopoles as messengers of cosmic magnetic fields, and discuss the possibility of using monopole experiments to probe intergalactic magnetic fields.