ADMX SLIC: Results from a Superconducting LC Circuit Investigating Cold Axions.

Abstract

Axions are a promising cold dark matter candidate. Haloscopes, which use the conversion of axions to photons in the presence of a magnetic field to detect axions, are the basis of microwave cavity searches such as the Axion Dark Matter eXperiment (ADMX). To search for lighter, low frequency axions in the sub- 2×10^{-7} eV (50MHz) range, a tunable lumped-element LC circuit has been proposed. For the first time, through ADMX SLIC (Superconducting LC Circuit Investigating Cold Axions), a resonant LC circuit was used to probe this region of axion mass-coupling space. The detector used a superconducting LC circuit with piezoelectric driven capacitive tuning. The axion mass and corresponding frequency ranges 1.7498-1.7519×10^{-7} eV (42.31-42.36MHz), 1.7734-1.7738×10^{-7} eV (42.88-42.89MHz), and 1.8007-1.8015×10^{-7} eV (43.54-43.56MHz) were covered at magnetic fields of 4.5T, 5.0T, and 7.0T, respectively. Exclusion results from the search data, for coupling below 10^{-12} GeV^{-1}, are presented.