Michael Jewell

New Results from HAYSTAC’s Dark Matter Axion Search with a Squeezed State Receiver

Abstract: Data from astrophysics and cosmology point to the existence of Cold Dark Matter in the Universe, for which a light axion is a well-motivated candidate. The HAYSTAC Experiment (Haloscope At Yale Sensitive To Axion CDM) is a microwave cavity search for axions with masses above 10 ueV/c^2. HAYSTAC, now in its second iteration, Phase II, employs a squeezed state receiver to achieve sub-quantum limited noise. I will report on details of the design and operation of the experiment previously used to search for axions in the mass ranges 16.96–17.12 and 17.14–17.28 ueV/c^2 (4.100–4.140 GHz and 4.145–4.178 GHz) as well as new results with an upgraded detector which extends our search to higher masses between 18.44–18.71 ueV/c^2 (4.459-4.523 GHz).