Search for Solar Axions via Axion-Photon Coupling with the Majorana Demonstrator

Area of Science:

• * Particle Physics
• * Astrophysics
• * Condensed Matter Physics

Background:

• * Axions were initially theorized to resolve the strong-CP problem in Quantum Chromodynamics (QCD).
• * The Sun is a potential source of axions due to axion-photon coupling.
• * Solid-state detection experiments can measure axions, potentially enhanced by coherent Primakoff-Bragg scattering.

Purpose of the Study:

• * To search for solar axions using the Majorana Demonstrator experiment.
• * To establish new limits on the axion-photon coupling constant.
• * To improve laboratory-based constraints for axion masses in a specific range.

Main Methods:

• * Utilized a set of ^{76}Ge-enriched high-purity germanium detectors.
• * Analyzed a 33 kg-yr exposure of data collected from January 2017 to November 2019.
• * Performed a temporal-energy analysis of the collected data.

Main Results:

• * Established a new upper limit on the axion-photon coupling constant: g_{aγ}<1.45×10^{-9} GeV^{-1} at 95% confidence level.
• * The limit applies to axions with masses up to 100 eV/c^{2}.
• * This result improves upon existing laboratory-based limits for axion masses between approximately 1 eV/c^{2} and 100 eV/c^{2}.

Conclusions:

• * The Majorana Demonstrator experiment has provided the most stringent laboratory-based limits on solar axion-photon coupling in the 1-100 eV/c^{2} mass range.
• * The findings contribute to the ongoing search for axions and the understanding of fundamental physics.
• * Future experiments can build upon these results to further probe axion properties.