MoEDAL

MoEDAL. The Monopole and Exotics Detector at the LHC is a pioneering experiment at the world's most powerful particle accelerator. It is specifically designed as a dedicated search apparatus for exotic, long-lived particles that conventional detectors might miss. Its primary mission is the direct detection of the magnetic monopole, a hypothetical particle predicted by various theories beyond the Standard Model. The collaboration represents a unique approach within the high-energy physics program at CERN, employing passive detection techniques alongside traditional electronic systems.

Overview and Purpose

The primary objective is to conduct a direct, model-independent search for magnetic monopoles and other highly ionizing exotic particles. This quest is motivated by profound theoretical implications from quantum mechanics and grand unified theories, such as those proposed by Paul Dirac and Gerard 't Hooft. Unlike most experiments at the Large Hadron Collider that focus on high-interaction-rate processes, it is optimized for rare-event signatures. Its purpose complements the broader physics program of major detectors like ATLAS and CMS by probing a different region of potential new phenomena.

Experimental Design and Location

The detector is installed at the LHCb interaction point on the Large Hadron Collider ring, a location chosen for its relatively low-radiation environment. Its core design utilizes stacks of passive plastic nuclear track detectors, similar to those used in cosmic ray research, which are permanently damaged by the passage of heavily ionizing particles. These detectors are supplemented by arrays of Timepix pixel chips and trapping volumes filled with paramagnetic materials designed to capture magnetically charged particles. This hybrid design allows for both the visualization of particle tracks and the potential physical extraction of captured specimens for further analysis in a laboratory.

Physics Goals and Detection Strategy

Its central physics goal is the discovery of the magnetic monopole, which would provide evidence for charge quantization and revolutionize electromagnetism. The experiment also searches for other hypothetical particles like strangelets, Q-balls, and massive, long-lived particles predicted by supersymmetry and theories with extra dimensions. The detection strategy relies on these particles' high ionization signatures, which leave etchable tracks in the plastic detectors. For monopoles, a complementary strategy uses the trapping volumes, which would be scanned using SQUID magnetometers after exposure to LHC collisions.

Notable Results and Discoveries

The collaboration has established the world's most stringent mass limits for magnetic monopoles at collider energies across various spin and charge models, significantly surpassing previous bounds set by experiments like the Fermilab Tevatron's D0 and CDF. It has also placed leading constraints on the production of multiply charged, long-lived particles and exotic objects like dyons. While a definitive discovery remains elusive, the published results in journals like Physical Review Letters have critically constrained the parameter space for many theories of new physics. The experiment continues to analyze data from Run 2 and Run 3 of the Large Hadron Collider.

Collaboration and Timeline

The international collaboration is led by spokespersons from institutions including the University of Alberta and Imperial College London, involving physicists from over twenty institutes worldwide. The proposal was approved by the CERN Research Board in 2010, with installation completed in time for the LHC's Run 2 in 2015. Major upgrades were implemented for Run 3, including the MAPP (MoEDAL Apparatus for Penetrating Particles) sub-detector to enhance sensitivity. The collaboration works in close synergy with the neighboring LHCb detector and maintains ties with other searches at facilities like the Pierre Auger Observatory.

Category:Experiments at the Large Hadron Collider Category:Particle physics experiments Category:CERN