Using Axion Miniclusters to Disentangle the Axion-photon Coupling and the Dark Matter Density

TL;DR

This paper proposes a method to disentangle the axion-photon coupling from dark matter density by using axion miniclusters and spectral data in haloscope experiments, enabling separate measurements of these parameters.

Contribution

It introduces a novel approach leveraging axion miniclusters and spectral information to independently measure axion-photon coupling and dark matter density.

Findings

Spectral data can reveal the gravitational potential of axion miniclusters.

This method allows separate determination of axion-photon coupling and dark matter density.

Potential to improve understanding of axion properties and dark matter distribution.

Abstract

Dark matter direct (and indirect) detection experiments usually can only determine a specific combination of a power of the coupling and the dark matter density. This is also true for axion haloscopes which are sensitive to the product $g^{2}_{a\gamma\gamma}\rho_{\rm DM}$, the combination of axion-photon coupling squared and the dark matter density. In this note we show, that in the lucky case when we intersect with a so-called axion minicluster of a suitable size, we can utilize the spectral information available in haloscopes to determine the gravitational potential of the minicluster. We can then use this to measure separately the coupling and the density of the minicluster.