Listening for echo from the stimulated axion decay with the 21 CentiMeter Array

TL;DR

This paper explores the potential of the 21 CentiMeter Array to detect axion dark matter decay signals by using stimulated emission, aiming to improve sensitivity beyond current limits.

Contribution

It presents a novel sensitivity study for axion detection via stimulated decay signals using the 21CMA, covering a specific mass range with a proposed two-year observation plan.

Findings

Sensitivity could surpass existing limits by about one order of magnitude.

The study covers axion masses between 0.41 and 1.6 μeV.

A two-year observation with a 1MW emitter is proposed.

Abstract

The axion is a hypothetical elementary particle that could solve the long-standing strong CP problem in particle physics and the dark matter mystery in the cosmos. Due to the stimulation of the ambient photons, the axion dark matter decay into photons is significantly enhanced so that its echo signal could be detected by terrestrial telescopes. As a pathfinder, we study the expected sensitivity of searching for the axion dark matter in the mass range between $0.41$ and $1.6\mu\text{eV}$ with the 21 CentiMeter Array (21CMA). We aim to cover the whole 21CMA frequency range in two years by using a 1MW emitter. We find that the resulting sensitivity on the axion-photon coupling could surpass other existing limits by about one order of magnitude.