Physicists have long suspected the existence of magnetic monopoles, particles that possess a north or south pole without its counterpart. Although these elusive monopoles have not been found yet, new data from the Large Hadron Collider (LHC) has allowed researchers to narrow down the possible energy range where they could reside.

The concept of magnetic monopoles was originally proposed by physicist Paul Dirac. He suggested that the presence of magnetic monopoles would be consistent with quantum mechanics and could explain certain unexplained features of electric charge. According to Dirac’s theory, the smallest possible magnetic charge for a single monopole is 68.5 times the charge of an electron, with larger monopoles being multiples of this charge.

In the 1970s, the search for magnetic monopoles gained momentum as it became a key test for theories seeking to unify general relativity and quantum mechanics. Although there have occasionally been reports of the discovery of magnetic monopoles, they have often been retracted or cases of misinformation.

The ATLAS collaboration at CERN, using data from the LHC, has identified two possible mechanisms through which high-energy collisions between protons could create magnetic monopoles with masses up to 4 TeV. Both mechanisms involve the emission of virtual photons by the protons. In one scenario, a virtual photon creates a magnetic monopole on its own, and in the other, two photons interact to create a monopole. Either of these scenarios would restore the broken electric-magnetic dual symmetry in Maxwell’s equations.

ATLAS is searching for evidence of magnetic monopoles by looking for charge deposits in its detector. Since a monopole would carry a much larger charge than an electron, its deposits should stand out from those of other subatomic particles.

Although ATLAS has not yet found direct evidence of magnetic monopoles, their analysis of LHC data from 2015-2018 has allowed them to reduce the possible masses and production rates of the smallest monopoles by a factor of three.

Although it may seem like an endless search, the physics community believes in the importance of finding magnetic monopoles. Not only would their discovery validate the theories that predict their existence, but the masses of these monopoles could also differentiate between competing theories.

The research article discussing these findings has been submitted to the Journal of High Energy Physics and is available as a preprint on

– CERN (ATLAS collaboration)
– Journal of High Energy Physics (preprint)