First Dark Photon Search Results from the Dandelion Experiment

TL;DR

This paper reports the first search for 1 meV dark photon dark matter using a spherical mirror and KID detectors, setting new upper limits on the kinetic mixing parameter in the 0.6-1.4 meV mass range.

Contribution

It introduces a novel experimental approach combining a spherical mirror and KID detectors for dark photon detection at millimeter wavelengths.

Findings

No dark photon signal detected, consistent with zero.

Set new upper limits on dark photon kinetic mixing parameter.

First constraints on dark photons using KID array at millimeter wavelengths.

Abstract

This paper presents the first results from the Dandelion experiment, a directional detection, which searches for 1 meV dark photon dark matter. We use a spherical mirror to convert dark photons into standard millimeter-wavelength photons that can then be detected with an array of 221 Kinetic Inductance Detectors (KIDs) cooled down to 150 mK within the KISS-NIKA camera ( (KIDs Interferometric Spectral Surveyor) and operating between 150 and 350 GHz. We used 1480 minutes of data to search for the signal of dark photons in the KID detectors, which is expected to be modulated due to the Earth's rotation. Our main challenge was to deal with a large background from room temperature and stray-light fluctuations. We used a de-correlation analysis to remove these background fluctuations. Templates of the background fluctuations were constructed from a Principal Component Analysis decomposition of detector measurements outside the expected Field of View trajectory of dark photons. We found that the dark photon signal was consistent with zero, giving a new upper limit on the dark photon's kinetic mixing, $\chi$, with masses between 0.6 meV and 1.4 meV. These are the first constraints on dark photons as a dark matter candidate using an array of KIDs at millimeter wavelength.