Searching for GUT-scale QCD Axions and Monopoles with a High Voltage Capacitor

TL;DR

This paper proposes a novel experimental method using a high voltage capacitor to search for GUT-scale QCD axions and magnetic monopoles, expanding the search beyond traditional QED coupling parameters.

Contribution

It introduces a new experimental approach to detect heavy monopoles and GUT-scale axions via axion electrodynamics couplings $g_{aEM}$ and $g_{aMM}$, not relying on $g_{a ext{γγ}}$.

Findings

Proposes using a high voltage capacitor to detect axion-monopole effects.

Suggests the method can distinguish heavy monopoles from axions.

Provides a new avenue for experimental searches in the GUT-scale mass range.

Abstract

The QCD axion has been postulated to exist because it solves the strong CP problem. Furthermore, if it exists axions should be created in the early Universe and could account for all the observed dark matter. In particular, axion masses of order $10^{-10}$ to $10^{-7}$ eV correspond to axions in the vicinity of the GUT-scale. In this mass range many experiments have been proposed to search for the axion through the standard QED coupling parameter $g_{a\gamma\gamma}$. Recently axion electrodynamics has been expanded to include two more coupling parameters, $g_{aEM}$ and $g_{aMM}$, which could arise if heavy magnetic monopoles exist. In this work we show that both $g_{aMM}$ and $g_{aEM}$ may be searched for using a high voltage capacitor. Since the experiment is not sensitive to $g_{a\gamma\gamma}$, it gives a new way to search for effects of heavy monopoles if the GUT-scale axion is shown to exist, or to simultaneously search for both the axion and the monopole at the same time.