Constraints on Axion couplings from the CDEX-1 experiment at the China Jinping Underground Laboratory

TL;DR

This paper reports on the search for axions using the CDEX-1 detector, setting new limits on axion couplings and excluding certain axion mass ranges, thereby advancing constraints on axion models.

Contribution

First experimental constraints on solar and dark matter axions using CDEX-1 data, improving existing limits and excluding specific axion mass ranges.

Findings

No excess signals observed in data.

Set new upper limits on axion-electron and axion-nucleon couplings.

Excluded axion masses heavier than 0.9 eV/c² (DFSZ) and 173 eV/c² (KSVZ).

Abstract

We report the results of searches for solar axions and galactic dark matter axions or axion-like particles with CDEX-1 experiment at the China Jinping Underground Laboratory, using 335.6 kg-days of data from a p-type point-contact germanium detector. The data are compatible with the background model and no excess signals are observed. Limits of solar axions on the model independent coupling $g_{Ae}<2.5\times10^{-11}$ from Compton, bremsstrahlung, atomic-recombination and deexcitation channel and $g^{\text{eff}}_{AN}\times g_{Ae}<6.1\times10^{-17}$ from $^{57}$Fe M1 transition at 90 % confidence level are derived. Within the framework of the DFSZ and KSVZ models, our results exclude the axion mass heavier than 0.9 eV/c$^{2}$ and 173 eV/c$^{2}$, respectively. The derived constraints for dark matter axions below 1 keV improves over the previous results.