RESUMO
We present first results from a dark photon dark matter search in the mass range from 44 to 52 µeV (10.7-12.5 GHz) using a room-temperature dish antenna setup called GigaBREAD. Dark photon dark matter converts to ordinary photons on a cylindrical metallic emission surface with area 0.5 m^{2} and is focused by a novel parabolic reflector onto a horn antenna. Signals are read out with a low-noise receiver system. A first data taking run with 24 days of data does not show evidence for dark photon dark matter in this mass range, excluding dark photon photon mixing parameters χâ³10^{-12} in this range at 90% confidence level. This surpasses existing constraints by about 2 orders of magnitude and is the most stringent bound on dark photons in this range below 49 µeV.
RESUMO
We introduce the Broadband Reflector Experiment for Axion Detection (BREAD) conceptual design and science program. This haloscope plans to search for bosonic dark matter across the [10^{-3},1] eV ([0.24, 240] THz) mass range. BREAD proposes a cylindrical metal barrel to convert dark matter into photons, which a novel parabolic reflector design focuses onto a photosensor. This unique geometry enables enclosure in standard cryostats and high-field solenoids, overcoming limitations of current dish antennas. A pilot 0.7 m^{2} barrel experiment planned at Fermilab is projected to surpass existing dark photon coupling constraints by over a decade with one-day runtime. Axion sensitivity requires <10^{-20} W/sqrt[Hz] sensor noise equivalent power with a 10 T solenoid and 10 m^{2} barrel. We project BREAD sensitivity for various sensor technologies and discuss future prospects.