Axion dark matter search with Dine-Fischer-Srednicki-Zhitnitskii sensitivity at IBS-CAPP

Abstract

The axion is a well-motivated particle that provides a solution to the strong $CP$ problem and is also a candidate for cold dark matter. The CAPP-12TB experiment is the flagship axion dark matter experiment at the Institute for Basic Science's Center for Axion and Precision Physics Research. The system consists of a superconducting solenoid with a bore size of 320 mm and a maximum central field of 12 T, a cryogenic dilution fridge with physical temperatures around 25 mK with cavity load, and a nearly quantum-noise-limited flux-driven Josephson parametric amplifier as the first amplifier of the receiver chain. The experiment uses a copper microwave cavity that has a large volume (37 L) and an unloaded Q-factor around 100,000 at low temperatures along its frequency range tuned by a copper rod. I report the first results of the experiment which excludes the Dine-Fischler-Srednicki-Zhitnitskii (DFSZ) axion model for the mass range 4.51 $\mu$eV (1.09 GHz) to 4.59 $\mu$eV (1.11 GHz) at a 90% confidence level. The CAPP-12TB experiment will continue its search for DFSZ axions over a wider range of axion masses using various cavities and amplifiers.