New studies that utilized a retired segment of the beam pipe from the Large Hadron Collider (LHC) at CERN have brought researchers significantly closer to testing the potential existence of magnetic monopoles. These findings present the most rigorous limitations to date regarding the existence of magnetic monopoles, enhancing our understanding of these mysterious particles.
New studies that utilized a retired segment of the beam pipe from the Large Hadron Collider (LHC) at CERN have brought researchers significantly closer to testing the potential existence of magnetic monopoles.
A research team from the University of Nottingham, collaborating with an international group, has established the strongest limits so far on the presence of magnetic monopoles, thereby expanding the knowledge surrounding these elusive particles. Their findings have been published in Physical Review Letters today.
In the realm of particle physics, a magnetic monopole is a theoretical elementary particle that behaves as an isolated magnet with just one magnetic pole (either a north pole without a south pole or vice versa).
Oliver Gould, the lead theorist of the study and a Dorothy Hodgkin Fellow at the School of Physics and Astronomy at the University of Nottingham, remarked: “Is it possible that there are particles possessing only a single magnetic pole—either north or south? This fascinating idea has been explored by esteemed physicists like Pierre Curie, Paul Dirac, and Joseph Polchinski, and it remains one of the most intriguing enigmas in theoretical physics. Proving the existence of these particles would revolutionize physics, yet experimental efforts have thus far yielded no results.”
The researchers concentrated their investigation on a retired section of the beam pipe from the LHC at CERN, monitored by physicists from the Monopole and Exotics Detector at the LHC (MoEDAL) experiment. They studied a beryllium beam pipe segment that had been positioned at the particle collision site for the Compact Muon Solenoid (CMS) experiment. This pipe had been subjected to radiation from countless ultra-high-energy ion collisions that took place mere centimeters away.
“Being close to where ultra-relativistic heavy ions collided offers an unparalleled opportunity to investigate monopoles with extremely high magnetic charges,” stated Aditya Upreti, a Ph.D. candidate who led the experimental analysis as part of Professor Ostrovskiy’s MoEDAL group at the University of Alabama. “Because magnetic charge is conserved, monopoles cannot decay and are anticipated to become trapped within the pipe’s material, which enables us to effectively search for them using a device specifically tuned to detect magnetic charge.”
The research team examined how magnetic monopoles might be produced during heavy ion collisions at the LHC, which create magnetic fields even more intense than those found around rapidly rotating neutron stars. These powerful fields could potentially facilitate the spontaneous generation of magnetic monopoles through the Schwinger mechanism.
Oliver added: “Even though the beam pipe is an old component slated for disposal, our calculations suggested it might be the most likely location on the planet to discover a magnetic monopole.”
The MoEDAL collaboration employed a superconductive magnetometer to survey the beam pipe for signs of captured magnetic charge. Although no evidence of magnetic monopoles was uncovered, their findings eliminate the possibility of monopoles weighing less than 80 GeV/c² (where c is the speed of light) and offer leading constraints for magnetic charges ranging from 2 to 45 basic units.
The research team intends to broaden their investigation moving forward. Oliver concluded: “The beam pipe we examined was from the LHC’s initial run, which occurred before 2013 at lower energy levels. Expanding the study to a more recent run at higher energies could potentially double our experimental capabilities. We are also exploring entirely different strategies for searching for magnetic monopoles.”
