Patras 2022 - 35 - Osamu Tajima - First results of the DOSUE-RR experiment

Dr. Osamu Tajima from the Kyoto University, Japan, talks about "First results of the DOSUE-RR experiment - search for dark photon CDM in the mass range 74 − 110 μeV/c2" at the 17th Patras Workshop on Axions, WIMPs and WISPs.
The Patras Workshop took place at the Johannes Gutenberg University of Mainz as the second week of events within the Wavy Dark Matter Summer event series in August 2022. www.wavydarkmatter.org
Abstract:
Dark photon cold dark matter (CDM) is one of the WISPs. Darkmatter
Observing System for Un-Explored Radio-Range (DOSUERR)
is a series of experiments to search for the dark photon CDM
using millimeter-wave spectroscopy. The dark photons convert to
ordinary photons at the boundary of electromagnetic fields such
as a metal surface. The frequency of the conversion photon corresponds
to the mass of the dark photon CDM owing to the energy
conservation, i.e., hν ~ mc2. We aim to detect the signal
in the frequency spectrum. For the first experiment, we developed
a cryogenic millimeter-wave receiver in a frequency range
18 − 26.5 GHz, which corresponds to a dark photon mass range
74 − 110 μeV/c2. Our first search was performed for two weeks
in 2021. We found no signal of the dark photon CDM, and set
an upper limit on the coupling constant between dark photons and
ordinary photons below (0.3 − 2.0) × 10^−10 at 95% confidence
level. This is the most stringent constraint to date, and tighter
than indirect constraints from cosmological observations. In this
workshop, we will present our first results and future prospects.
arxiv.org/abs/...