Dynamical Rearrangement of Theta Parameter in Presence of Mixed Chern-Simons Term

TL;DR

This paper investigates how the theta parameter in a five-dimensional gauge theory with a mixed Chern-Simons term can be dynamically rearranged or removed through gauge transformations, utilizing the Hosotani mechanism.

Contribution

It demonstrates that the theta parameter can be viewed as a boundary condition and can be dynamically eliminated via large gauge transformations in the presence of a mixed Chern-Simons term.

Findings

The theta parameter can be removed by large gauge transformations.

The Hosotani mechanism enables dynamical rearrangement of theta.

The physics remains invariant despite changes in the action.

Abstract

We study the five-dimensional SU(3)_c x U(1)_C gauge theory on the orbifold S^1/Z_2 with a mixed Chern-Simons term. We particularly pay attention to the realization of the dynamical rearrangement of the theta parameter for SU(3)_c. It is shown that the physics remains invariant under a large gauge transformation which even changes the action, completely removing the theta parameter, because of the Hosotani mechanism for the U(1)_C gauge interactions. In other words, we show that the theta parameter can be regarded as a boundary condition for the orbifolding in light of the dynamical rearrangement.