PNNL

Abstract

Axions were originally proposed to explain the strong-CP problem in QCD. Axions and axion-like particles are also well-motivated dark matter candidates. Through the axion-photon coupling, the Sun could be a major source of axions, which could be detected in Earth-based solid-state detection experiments. The Majorana Demonstrator experiment has searched for solar axions with a set of 76Ge-enriched high purity germanium detectors, using a 33 kg-yr exposure collected between Jan. 2017 and Nov. 2019. Accounting for enhancements in the detection rate due to coherent Primakoff-Bragg scattering, a two-dimensional analysis in energy and time gives a new limit on the axion-photon coupling as ga