Search for Dark Photon Dark Matter in the Mass Range $74\mbox{--}110\,\mu\mathrm{eV}/c^2$ with a Cryogenic Millimeter-Wave Receiver

TL;DR

This study searches for dark photon dark matter within a specific mass range using a cryogenic millimeter-wave receiver, setting the most stringent constraints to date on the kinetic coupling constant and improving detection methods.

Contribution

First experimental search for dark photon dark matter in the 74-110 μeV/c^2 range using cryogenic millimeter-wave technology, establishing new upper bounds on the coupling constant.

Findings

No significant signal detected, setting upper bounds on coupling constant.

Achieved the most stringent constraints to date on dark photon dark matter.

Enhanced sensitivity through cryogenic optical path and fast spectrometer.

Abstract

We search for the dark photon dark matter (DPDM) using a cryogenic millimeter-wave receiver. DPDM has a kinetic coupling with electromagnetic fields with a coupling constant of $\chi$, and is converted into ordinary photons at the surface of a metal plate. We search for signal of this conversion in the frequency range $18\text{--}26.5\,\mathrm{GHz}$, which corresponds to the mass range $74\text{--}110\,mu\mathrm{eV}/c^2$. We observed no significant signal excess, allowing us to set an upper bound of $\chi < (0.3\text{--}2.0)\times 10^{-10}$ at 95\% confidence level. This is the most stringent constraint to date, and tighter than cosmological constraints. Improvements from previous studies are obtained by employing a cryogenic optical path and a fast spectrometer.