Axion Searches with Two Superconducting Radio-frequency Cavities

TL;DR

This paper proposes a novel experimental setup using two superconducting RF cavities to search for Axion-like particles, potentially exploring new parameter space with enhanced sensitivity and noise mitigation strategies.

Contribution

Introduction of a new light-shining-through-wall experimental setup with dual RF cavities for improved ALP detection sensitivity.

Findings

Potential to explore new ALP parameter space

Enhanced sensitivity with high-level modes and phase matching

Noise effects can be mitigated through frequency separation

Abstract

We propose an experimental setup to search for Axion-like particles (ALPs) using two superconducting radio-frequency cavities. In this light-shining-through-wall setup the axion is sourced by two modes with large fields and nonzero $\vec E\cdot \vec B$ in an emitter cavity. In a nearby identical cavity only one of these modes, the spectator, is populated while the other is a quiet signal mode. Axions can up-convert off the spectator mode into signal photons. We discuss the physics reach of this setup finding potential to explore new ALP parameter space. Enhanced sensitivity can be achieved if high-level modes can be used, thanks to improved phase matching between the excited modes and the generated axion field. We also discuss the potential leakage noise effects and their mitigation, which is aided by O(GHz) separation between the spectator and signal frequencies.