# Line Operators in the Standard Model

## TL;DR

This paper explores how the choice of gauge group in the Standard Model affects the properties of line operators and the periodicity of theta angles, highlighting an ambiguity not resolved by current experiments.

## Contribution

It clarifies the dependence of line operators and theta angle periodicities on the subgroup a7 in the gauge group of the Standard Model.

## Key findings

- Line operators vary with different a7 choices.
- Theta angle periodicities differ based on the gauge group structure.
- The ambiguity in the gauge group affects observable topological features.

## Abstract

There is an ambiguity in the gauge group of the Standard Model. The group is $G = SU(3) \times SU(2) \times U(1)/\Gamma$, where $\Gamma$ is a subgroup of ${\bf Z}_6$ which cannot be determined by current experiments. We describe how the electric, magnetic and dyonic line operators of the theory depend on the choice of $\Gamma$. We also explain how the periodicity of the theta angles, associated to each factor of $G$, differ.