Z. She, L. P. Jia, Q. Yue et al.
Direct Detection Constraints on Dark Photons with the CDEX-10 Experiment at the China Jinping Underground Laboratory
Phys. Rev. Lett. 124, 111301 (2020)
We report constraints on the dark photon effective kinetic mixing parameter (κ) with data taken from two p-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90% confidence level upper limits on κ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (m_V) from 10 to 300 eV/c² in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90% confidence level with m_V from 0.1 to 4.0 keV/c² are set from 449.6 kg-day data, with a minimum of κ = 1.3 × 10⁻¹⁵ at m_V = 200 eV/c².