PandaX (Particle AND Astrophysical Xenon experiment) is a staged experiment aiming at direct dark matter and neutrinoless double beta decay searches at the China Jin-Ping Underground Laboratory. The first phase PandaX-I is a pancake-shaped 120 kg detector using a dual phase Xenon time projection chamber (TPC) technology. The low threshold of the detector allows us to probe the low mass WIMPdetection. After running for about 5 months at CJPL, the PandaX-I experiment was completed in 2014. With the full 80.1-day exposure data, we released the dark matter search results from PandaX-I this summer. No significant excess events were found above the expected background. The results also confirm our earlier finding with 17.4-day live data and strongly disfavor the all previously positive low-mass WIMP signals reported from DAMA/LIBRA, CRESST-II, CDMS-II Si, et al.In the direct dark matter search community with xenon, we achieved the best reported limit on WIMPs with mass below 5.5 GeV.

In this talk, I will introduce the apparatus of the PandaX-I experiment, and then present details of the physics analysis as well as the final results.

Host: Prof. Jianglai Liu