In the dark matter search experiment “DOSUE-RR,” a collaborative research team, including Associate Professor Adachi from our laboratory, has carried out a dark photon search using the millimeter-wave receiver developed in the FINER project (link) at the National Astronomical Observatory of Japan (NAOJ).
The FINER (Far-Infrared Nebular Emission Receiver) project is an effort to develop a high-sensitivity millimeter-wave receiver based on superconducting SIS mixers. The receiver is designed to be installed on the Large Millimeter Telescope (LMT, link) in Mexico for spectroscopic observations of distant galaxies. In this study, the receiver (210–350 GHz) enables a search for dark photons in the mass range of 0.9–1.4 meV.
In this experiment, calibration systems and a readout system (dSpec), developed in collaboration with Okayama University, the University of Tsukuba, and Kyoto University, were integrated into the FINER receiver at NAOJ, owing to the collaboration with the FINER team from NAOJ, Nagoya University, and UEC. Observations for dark photon detection commenced on April 6, 2026.
If successful, this measurement is expected to achieve the world’s highest sensitivity in this mass range for dark photon searches. We look forward to future results.
