On March 17th, CDEX (China Dark matter EXperiment) collaboration, led by Tsinghua University, published an article entitled “Direct Detection Constraints on Dark Photons with CDEX-10 Experiment at the China Jinping Underground Laboratory” on Physical Review Letters (Phys. Rev. Lett. 124, 111301).
        In this letter, the limits on the mixing parameters (κ) of solar dark photon at 90% confidence level (C.L.) have been set based on the data set of 205.4 kg·day exposure from C10-B1 detector with a minimal Chi Squared method. Meanwhile, combined with data set of   244.2 kg·day exposure from the C10-C1 detector, the exclusive limits on κ of dark photon dark matter at 90% C.L. are also analyzed. The results probe new parameters both for the κ of solar dark photon, the best limit from direct detection experiments to date, and of dark photon dark matter.                    

        Article link: https://doi.org/10.1103/PhysRevLett.124.111301

Figure 1. The exclusive limits of solar dark photons (Left) and dark photon dark mtter (Right)