Asteroids for ultralight dark-photon dark-matter detection

TL;DR

This paper proposes using asteroid-based gravitational-wave detectors to explore new parameter space for ultralight dark-photon dark matter, significantly surpassing current limits in specific mass ranges.

Contribution

It demonstrates how asteroid monitoring can extend sensitivity to ultralight dark-photon dark matter in previously unexplored mass ranges, improving detection prospects.

Findings

Sensitivity to dark-photon coupling exceeds current limits by up to a factor of 500.

Detects dark matter in the mass range 5-9 x 10^{-21} eV to 2 x 10^{-19} eV.

Potential extension up to 2 x 10^{-18} eV with noise mitigation.

Abstract

Gravitational-wave (GW) detectors that monitor fluctuations in the separation between inertial test masses (TMs) are sensitive to new forces acting on those TMs. Ultralight dark-photon dark matter (DPDM) coupled to $U(1)_B$ or $U(1)_{B-L}$ charges supplies one such force that oscillates with a frequency set by the DPDM mass. GW detectors operating in different frequency bands are thus sensitive to different DPDM mass ranges. A recent GW detection proposal based on monitoring the separation of certain asteroids in the inner Solar System would have sensitivity to $\mu$Hz frequencies [arXiv:2112.11431]. In this paper, we show how that proposal would also enable access to new parameter space for DPDM coupled to $B$ [respectively, $B-L$] charges in the mass range $5\ [9] \times 10^{-21} \text{eV} \lesssim m_{\text{DM}} \lesssim 2 \times 10^{-19} \text{eV}$, with peak sensitivities about a factor of 500 [50] beyond current best limits on $\varepsilon_B$ [$\varepsilon_{B-L}$] at $m_{\text{DM}} \sim 2 \times 10^{-19} \text{eV}$. Sensitivity could be extended up to $m_{\text{DM}} \sim 2 \times 10^{-18} \text{eV}$ only if noise issues associated with asteroid rotational motion could be overcome.