Axion Dark Matter Search with Near-KSVZ Sensitivity Using the TM$_{020}$ Mode

TL;DR

This paper reports a sensitive search for axion dark matter around 21 μeV using the TM020 mode of a cylindrical cavity, achieving 1.7 times the KSVZ sensitivity over 100 MHz, thus extending the search to higher masses.

Contribution

The work introduces a novel cavity tuning mechanism enabling high-sensitivity axion searches at higher masses around 21 μeV using the TM020 mode.

Findings

Achieved 1.7 times KSVZ sensitivity over 100 MHz

Extended axion search range to higher masses around 21 μeV

Demonstrated effective use of the TM020 mode with innovative tuning

Abstract

Dark matter remains one of the most profound mysteries in modern physics, with axions, a hypothetical particle proposed to resolve the strong CP problem, standing as a compelling candidate. Among various experimental strategies, cavity haloscopes currently offer the most sensitive method to detect axions, though their searches have largely been confined to axion masses below 10 $\mu$eV. However, recent theoretical developments suggest that the axion mass lies beyond this range. Higher-order cavity modes have been explored as a methodological approach to expand the search range, albeit with limited success in achieving both high sensitivity and broad tunability. In this work, we present a sensitive search for axions with masses around 21 $\mu$eV, utilizing the TM$_{020}$ mode of a cylindrical cavity, which incorporated an innovative tuning mechanism. Our results reached 1.7 times the KSVZ sensitivity over 100 MHz, representing a significant improvement in this mass range and contributing to the experimental search for axion dark matter at higher masses.