A warped relaxion

TL;DR

This paper presents a UV completion of the relaxion mechanism within a warped extra dimension, identifying the relaxion with a gauge field component and demonstrating how hierarchical decay constants can be achieved through localization effects.

Contribution

It introduces a novel warped extra-dimensional framework for the relaxion, enabling hierarchical decay constants and a high cutoff scale for the relaxion model.

Findings

Hierarchical decay constants achieved via localization in warped space

Relaxion identified with zero mode of a bulk gauge field

Cutoff scale of the model can reach up to 10^6 GeV

Abstract

We construct a UV completion of the relaxion in a warped extra dimension. We identify the relaxion with the zero mode of the fifth component of a bulk gauge field and show how hierarchically different decay constants for this field can be achieved by different localizations of anomalous terms in the warped space. This framework may also find applications for other axion-like fields. The cutoff of the relaxion model is identified as the scale of the IR brane where the Higgs lives, which can be as high as $10^6$ GeV, while above this scale warping takes over in protecting the Higgs mass.