Electroweak monopoles and magnetic dumbbells in grand unified theories

TL;DR

This paper demonstrates the theoretical existence of electroweak monopoles and magnetic dumbbells within grand unified theories like SU(5), predicting their properties, masses, and potential for detection in high-energy collider experiments.

Contribution

It introduces the concept of electroweak monopoles and magnetic dumbbells in SU(5) GUTs, detailing their magnetic charges, masses, and topological structures, which were not previously established.

Findings

Electroweak monopoles carry specific magnetic charges consistent with Dirac quantization.

Monopoles are predicted to have masses around 700 GeV, with dumbbells in the TeV range.

Presence of these structures offers new experimental tests for GUTs in colliders.

Abstract

We use the $SU(5)$ model to show the presence in grand unified theories of an electroweak monopole and a magnetic dumbbell ("meson") made up of a monopole-antimonopole pair connected by a $Z$-magnetic flux tube. The monopole is associated with the spontaneous breaking of the weak $SU(2)_L$ gauge symmetry by the induced vacuum expectation value of a heavy scalar $SU(2)_L$ triplet with zero weak hypercharge contained in the adjoint Higgs 24-plet. This monopole carries a Coulomb magnetic charge of $(3/4) (2\pi/e)$ as well as $Z$-magnetic charge, where $2\pi/e$ denotes the unit Dirac magnetic charge. Its total magnetic charge is $\sqrt{3/8}(4\pi/e)$, which is in agreement with the Dirac quantization condition. The monopole weighs about 700 GeV, but because of the attached $Z$-magnetic tube it exists, together with the antimonopole, in a magnetic dumbbell configuration whose mass is expected to lie in the TeV range. The presence of these topological structures in $SU(5)$ and $SO(10)$ and in their supersymmetric extensions provides an exciting new avenue for testing these theories in high-energy colliders.