We report the results of searches for solar axions and galactic dark matter axions or axionlike particles with the 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 $g_{Ae}<2.5\times {10}^{-11}$ from Compton, bremsstrahlung, atomic-recombination, and deexcitation channels and $g_{AN}^{\text{eff}}\times g_{Ae}<6.4\times {10}^{-17}$ from a ${}^{57}\mathrm{Fe}$ M1 transition at 90% confidence level are derived. Within the framework of the Dine-Fischler-Srednicki-Zhitnitskiy and Kim-Shifman-Vainshtein-Zakharov models, our results exclude the axion mass heavier than 0.9 and $177\mathrm{eV}/{\mathrm{c}}^2$, respectively. The derived constraints for dark matter axions below 1 keV improve over the previous results.

• Received 24 October 2016

DOI:https://doi.org/10.1103/PhysRevD.95.052006