An Electroweak Monopole, Dirac Quantization and the Weak Mixing Angle

TL;DR

This paper explores an extension of the Standard Model that predicts electroweak monopoles and relates the Dirac quantization condition to the weak mixing angle, aligning theoretical predictions with experimental measurements.

Contribution

It introduces a model with magnetic monopoles that predicts the weak mixing angle using topological and Dirac quantization conditions, connecting monopole physics with electroweak parameters.

Findings

Predicts ${\rm sin}^2\theta_W = 1/4$ at monopole mass scale

Renormalization-group analysis yields ${\rm sin}^2\theta_W \approx 0.231$ at $Z$-boson mass

Monopole mass is of order a few TeV

Abstract

We consider an extension of the Standard Model that was proposed recently by one of the current authors (PQH), which admits magnetic monopoles with a mass of order of a few TeV. We impose, in addition to topological quantization in the SU(2) sector of the model, the Dirac Quantization Condition (DQC) required for consistency of the quantum theory of a charged electron in the presence of the monopole. This leads to the prediction ${\rm sin}^2\theta_W = 1/4$, where $\theta_W$ is the weak mixing angle at the energy scale set by the monopole mass. A leading-order renormalization-group analysis yields the value of ${\rm sin}^2 \theta_W \simeq 0.231$ at the $Z$-boson mass, as measured by experiment, under suitable conditions on the spectrum of the extra particles in the model.