Axion-Like Particle Production at Beam Dump Experiments with Distinct Nuclear Excitation Lines

TL;DR

This paper proposes a novel method for searching for axion-like particles using monoenergetic nuclear de-excitation photons in beam dump experiments, demonstrating potential to explore new parameter space and improve detection sensitivity.

Contribution

It introduces a new experimental approach utilizing nuclear de-excitation photons for ALP searches, expanding the scope beyond traditional methods.

Findings

IsoDAR can set limits on ALP-photon coupling.

Method can explore large regions of ALP parameter space.

Design considerations for isotope decay-at-rest experiments are discussed.

Abstract

Searches for axion-like particles (ALPs) are motivated by the strong CP problem in particle physics and by unexplained dark matter in astrophysics. In this letter, we discuss novel ALP searches using monoenergetic nuclear de-excitation photons from a beam dump, using IsoDAR as an example. We show that IsoDAR can set limits that close a gap in traditional QCD axion searches using the ALP-photon coupling, as well as provide sensitivity to large regions of new parameter space in models where ALPs couple to nucleons and electrons. We also show how isotope decay-at-rest experiments may be designed to improve potential ALP production and optimize detection sensitivity.