The axion is a promising dark matter candidate, which was originally proposed to solve the strong-CP problem in particle physics. To date, the available parameter space for axion and axion-like particle dark matter is relatively unexplored, particularly at masses ma 1 µeV. ABRACADABRA is a new experimental program to search for axion dark matter over a broad range of masses, 10 −12 ma 10 −6 eV. ABRACADABRA-10 cm is a small-scale prototype for a future detector that could be sensitive to the QCD axion. In this Letter, we present the first results from a 1 month search for axions with ABRACADABRA-10 cm. We find no evidence for axion-like cosmic dark matter and set 95% C.L. upper limits on the axion-photon coupling between gaγγ < 1.4 × 10 −10 GeV −1 and gaγγ < 3.3 × 10 −9 GeV −1 over the mass range 3.1 × 10 −10 eV -8.3 × 10 −9 eV. These results are competitive with the most stringent astrophysical constraints in this mass range.

The past few years have seen a renewed interest in the search for light particle dark matter. ABRACADABRA is a new experimental program to search for axion dark matter over a broad range of masses, 10 −12 ma 10 −6 eV. ABRACADABRA-10 cm is a small-scale prototype for a future detector that could be sensitive to QCD axion couplings. In this paper, we present the details of the design, construction, and data analysis for the first axion dark matter search with the ABRACADABRA-10 cm detector. We include a detailed discussion of the statistical techniques used to extract the limit from the first result with an emphasis on creating a robust statistical footing for interpreting those limits.