Modulation and diurnal variation in axionic dark matter searches

TL;DR

This paper investigates how Earth's motion causes annual and diurnal variations in axion dark matter detection signals using resonant cavities, highlighting potential modulation effects and directional asymmetries.

Contribution

It introduces the concept of time-dependent effects, including annual and diurnal variations, in axion dark matter searches with resonant cavities, emphasizing the importance of directional detection.

Findings

Resonance width varies annually due to Earth's orbit.

Directional experiments show large asymmetries in width.

Diurnal variations arise from Earth's rotation.

Abstract

In the present work we study possible time dependent effects in Axion Dark Matter searches employing resonant cavities. We find that the width of the resonance, which depends on the axion mean square velocity in the local frame, will show an annual variation due to the motion of the Earth around the sun (modulation). Furthermore, if the experiments become directional, employing suitable resonant cavities, one expects large asymmetries in the observed widths relative to the sun's direction of motion. Due to the rotation of the Earth around its axis, these asymmetries will manifest themselves as a diurnal variation in the observed width.