American theoretical physicist Joseph Polchinski once said the existence of magnetic monopoles is ‘one of the safest bets that one can make about physics not yet seen.’ In its quest for these particles, which have a magnetic charge and are predicted by several theories that extend the Standard Model, the MoEDAL (Monopole and Exotics Detector at the LHC) Collaboration has not yet proven Polchinski right, but its latest findings mark a significant stride forward. The new results narrow the search window for these hypothetical particles.
At CERN’s Large Hadron Collider (LHC), pairs of magnetic monopoles could be produced in interactions between protons or heavy ions.
In collisions between protons, they could be formed from a single virtual photon (Drell-Yan mechanism) or the fusion of two virtual photons (photon-fusion mechanism).
Pairs of magnetic monopoles could also be produced from the vacuum in the enormous magnetic fields created in near-miss heavy-ion collisions, through a process called the Schwinger mechanism.
Since it started taking data in 2012, MoEDAL has achieved several firsts, including conducting the first searches at the LHC for magnetic monopoles produced via the photon-fusion mechanism and through the Schwinger mechanism.
In the first of its latest studies, the MoEDAL physicists sought monopoles and high-electric-charge objects (HECOs) produced via the Drell-Yan and photon-fusion mechanisms.
The search was based on proton-proton collision data collected during Run 2 of the LHC, using the full MoEDAL detector for the first time.
The full detector comprises two main systems sensitive to magnetic monopoles, HECOs and other highly ionizing hypothetical particles.
The first can permanently register the tracks of magnetic monopoles and HECOs, with no background signals from Standard Model particles. The second system consists of roughly a tonne of trapping volumes designed to capture magnetic monopoles.
In their latest scanning of the…
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