The ORGAN experiment: An axion haloscope above 15 GHz

We present first results and future plans for the Oscillating Resonant Group AxioN (ORGAN) experiment, a microwave cavity axion haloscope situated in Perth, Western Australia designed to probe for high mass axions motivated by several theoretical models. The first stage focuses around 26.6 GHz in order to directly test a claimed result, which suggests axions exist at the corresponding mass of 110 mu eV. Later stages will move to a wider scan range of 15-50 GHz (62-207 mu eV). We present the results of the pathfinding run, which sets a limit on g(alpha gamma gamma) of 2.02 x 10(-12) eV(-1) at 26.531 GHz, or 110 ae eV, in a span of 2.5 neV (shaped by the Lorentzian resonance) with 90% confidence. Furthermore, we outline the current design and future strategies to eventually attain the sensitivity to search for well known axion models over the wider mass range. (C) 2017 Elsevier B.V. All rights reserved.