Overview of the Cosmic Axion Spin Precession Experiment (CASPEr)

TL;DR

This paper reviews the CASPEr experiment, which uses nuclear magnetic resonance to search for axion and ALP dark matter, exploring new parameter spaces beyond current bounds and aiming to detect QCD axions.

Contribution

It provides an overview of the experimental approach and progress in using NMR techniques to detect axion-like particles as dark matter candidates.

Findings

First-stage experiments probe extensive ALP parameter space.

Future experiments aim to detect QCD axions with masses below 10^{-9} eV.

The method can potentially identify axion-induced nuclear effects.

Abstract

An overview of our experimental program to search for axion and axion-like-particle (ALP) dark matter using nuclear magnetic resonance (NMR) techniques is presented. An oscillating axion field can exert a time-varying torque on nuclear spins either directly or via generation of an oscillating nuclear electric dipole moment (EDM). Magnetic resonance techniques can be used to detect such an effect. The first-stage experiments explore many decades of ALP parameter space beyond the current astrophysical and laboratory bounds. It is anticipated that future versions of the experiments will be sensitive to the axions associated with quantum chromodynamics (QCD) having masses $\lesssim 10^{-9}~{\rm eV}/c^2$.