Experimental Searches for Magnetic Monopoles at Particle Colliders

Abstract

The concept of magnetic monopoles is almost as old as the study of magnetism itself. However, only since 1931, the year of publication of Dirac’s¹ classic paper, have monopoles had a fundamental role in modern physics. Of late, Grand Unified Theories have been able to provide predictions of the mass of the magnetic monopole, a parameter missing from Dirac’s analysis. Although recent investigations have concentrated on the detection of very heavy GUT monopoles there seem to be no serious theoretical constraints forbidding the existence of monopoles with lower mass. The experimental searches for such light monopoles described here were carried out at three particle colliders with large center of mass energies: the CERN ISR, the CERN SPS collider and PETRA at DESY.^2,3,4 The maximum center of mass energies and particle types were respectively 60 GeV (pp and pp), 540 GeV (pp̄) and 40 GeV (e⁺e⁻).