The Standard Model with one universal extra dimension

TL;DR

This paper provides a comprehensive quantization and analysis of the Standard Model extended with one universal extra dimension, focusing on gauge fixing, field mixing, and one-loop renormalizability.

Contribution

It introduces a gauge-fixing procedure and explicit couplings for the Standard Model with a universal extra dimension, ensuring one-loop renormalizability and cutoff independence.

Findings

Explicit expressions for physical couplings are derived.

The model is shown to be one-loop renormalizable.

Gauge and mass eigenstates are precisely connected.

Abstract

Effects of universal extra dimensions on Standard Model observables first arise at the one-loop level. The quantization of this class of theories is therefore essential in order to perform predictions. A comprehensive study of the Standard Model defined in a space-time manifold with one universal extra dimension, compactified on the oribifold $S^1/Z_2$, is presented. The fact that the four-dimensional Kaluza-Klein theory is subject to two types of gauge transformations is stressed and its quantization under the basis of the BRST symmetry discussed. A $SU_C(3) x SU_L(2) x U_Y(1)$-covariant gauge-fixing procedure for the Kaluza-Klein excitations is introduced. The connection between gauge and mass eigenstates fields is established in an exact way. An exhaustive list of the explicit expressions for all physical couplings induced by the Yang-Mills, Currents, Higgs, and Yukawa sectors is presented. The one-loop renormalizability of the standard Green's functions, which implies that the Standard Model observables do not depend on a cutoff scale, is stressed.