Search for hadronic axions using axioelectric effect

TL;DR

This paper reports a search for hadronic axions emitted by the Sun, using the axioelectric effect in a detector, setting an upper mass limit of 400 eV at 95% confidence.

Contribution

First experimental search for solar hadronic axions via the axioelectric effect, establishing new constraints on axion mass.

Findings

No axion signal detected.

Upper mass limit of 400 eV at 95% confidence.

Method demonstrates feasibility of axion detection via axioelectric effect.

Abstract

We made a search for hadronic axions which could be emitted from the Sun in M1 transitions between the first 14.4 keV thermally excited and the ground state in Fe-57, and absorbed in the HPGe detector by axioelectric effect. An upper limit on hadronic axion mass of 400 eV is obtained at the 95% confidence level.