[Paper Review] Magnetic monopoles

P. Giacomelli, L. Patrizii|arXiv (Cornell University)|Feb 14, 2000

Astrophysics and Cosmic Phenomena14 citations

TL;DR

This paper reviews experimental searches for magnetic monopoles across multiple theoretical frameworks: Dirac monopoles at particle accelerators, superheavy monopoles from Grand Unified Theories (GUTs) in cosmic radiation, intermediate-mass monopoles in extra-dimensional theories, and exotic particles like nuclearites and Q-balls. It synthesizes current detection efforts and constraints, emphasizing the interplay between theory and experimental limits.

ABSTRACT

We discuss the experimental situation of direct searches at accelerators for Dirac magnetic monopoles, and in the penetrating cosmic radiation for the superheavy magnetic monopoles predicted by GUT theories. We also discuss the searches for intermediate mass monopoles (wich are predicted by theories in extra dimensions), and for nuclearites and Q-balls.

Motivation & Objective

• To evaluate the current experimental status of direct searches for Dirac magnetic monopoles at particle accelerators.
• To assess the evidence and constraints for superheavy magnetic monopoles predicted by Grand Unified Theories (GUTs) in cosmic radiation.
• To examine the search strategies and experimental limits for intermediate-mass magnetic monopoles arising from theories with extra dimensions.
• To review the experimental status of searches for nuclearites and Q-balls, which are related to monopole-like phenomena.

Proposed method

• Analyzes data from high-energy collider experiments to set upper limits on the production cross-sections of Dirac magnetic monopoles.
• Reviews observational data from cosmic ray detectors to constrain the flux of superheavy magnetic monopoles predicted by GUTs.
• Evaluates theoretical models involving extra dimensions that predict intermediate-mass magnetic monopoles and their detectability via ionization or energy deposition.
• Considers detection techniques sensitive to highly ionizing, slow-moving particles, such as those expected from monopoles and Q-balls.
• Compares experimental signatures across different monopole types, focusing on energy deposition, ionization, and magnetic charge effects.
• Synthesizes results from multiple experimental collaborations to provide a comprehensive overview of current exclusion limits.

Experimental results

Research questions

• RQ1 What are the current experimental limits on the production of Dirac magnetic monopoles at particle accelerators?
• RQ2 What constraints do cosmic ray observations place on the flux of superheavy magnetic monopoles predicted by GUT theories?
• RQ3 How do models with extra dimensions predict the existence and detectability of intermediate-mass magnetic monopoles?
• RQ4 What are the experimental signatures and detection challenges for nuclearites and Q-balls in the context of monopole searches?
• RQ5 How do different monopole types (Dirac, GUT, extra-dimensional, exotic) compare in terms of detectable signals and current exclusion limits?

Key findings

• No direct evidence for Dirac magnetic monopoles has been observed in accelerator experiments, with production cross-sections constrained to be below current experimental sensitivity.
• Cosmic ray searches have placed strong upper limits on the flux of superheavy magnetic monopoles, consistent with predictions from GUT theories but not yet detecting any.
• Intermediate-mass magnetic monopoles from extra-dimensional models remain undetected, with experimental limits depending on their mass and magnetic charge.
• Searches for nuclearites and Q-balls have not yielded detections, and their existence remains speculative, with experimental constraints derived from ionization and energy deposition measurements.
• Theoretical models predict distinct detection signatures for different monopole types, but current experiments have not observed any such events.
• The paper concludes that while no monopoles have been detected, experimental efforts continue to set increasingly stringent limits across all monopole and exotic particle categories.