Generalized dyons and magnetic dipoles: the issue of angular momentum

TL;DR

This paper investigates the angular momentum properties of magnetic monopoles, dyons, and dipoles in generalized non-Abelian gauge theories, showing that monopoles cannot spin under typical asymptotic conditions despite having nonzero angular momentum density.

Contribution

It extends the analysis of monopole and dyon angular momentum to generalized models, demonstrating the generic non-spinning nature of monopoles with standard asymptotics.

Findings

Magnetic monopoles cannot spin with usual asymptotics.

Dyons and dipoles can have nonzero angular momentum density.

Results are consistent across various model generalizations.

Abstract

It is known that a non-Abelian magnetic monopole cannot rotate globally (although it may possess a nonzero angular momentum density). At the same time, the total angular momentum of a magnetic dipole equals the electric charge. In this work we question the generality of these results by considering a number of generalizations of the Georgi-Glashow model. We study two different types of finite energy, regular configurations: solutions with net magnetic charge and monopole-antimonopole pairs with zero net magnetic charge. These configurations are endowed with an electric charge and carry also a nonvanishing angular momentum density. However, we argue that the qualitative results found in the Georgi-Glashow model are generic and thus a magnetic monopole cannot spin as long as the matter fields feature the usual "monopole" asymptotic behaviour independently of the dynamics of the model. A study of the properties of the dyons and magnetic dipoles in some generalizations of the Georgi-Glashow model supplemented with higher order Skyrme-like terms in the gauge curvature and Higgs fields is given quantitatively.