Xun Chen

Dark Matter Results from First 98.7 Days of Data from the PandaX-II Experiment

We report the weakly interacting massive particle (WIMP) dark matter search results using the first physics-run data of the PandaX-II 500xa0kg liquid xenon dual-phase time-projection chamber, operating at the China JinPing underground laboratory. No dark matter candidate is identified above background. In combination with the data set during the commissioning run, with a total exposure of 3.3×10^{4}u2009u2009kgu2009day, the most stringent limit to the spin-independent interaction between the ordinary and WIMP dark matter is set for a range of dark matter mass between 5 and 1000u2009u2009GeV/c^{2}. The best upper limit on the scattering cross section is found 2.5×10^{-46}u2009u2009cm^{2} for the WIMP mass 40u2009u2009GeV/c^{2} at 90%xa0confidence level.

Dark Matter Results From 54-Ton-Day Exposure of PandaX-II Experiment

We report a new search for weakly interacting massive particles (WIMPs) using the combined low background data sets acquired in 2016 and 2017 from the PandaX-II experiment in China. The latest data set contains a new exposure of 77.1 live days, with the background reduced to a level of 0.8×10^{-3}u2009u2009evt/kg/day, improved by a factor of 2.5 in comparison to the previous run in 2016. No excess events are found above the expected background. With a total exposure of 5.4×10^{4}u2009u2009kgu2009day, the most stringent upper limit on the spin-independent WIMP-nucleon cross section is set for a WIMP with mass larger than 100u2009u2009GeV/c^{2}, with the lowest 90%xa0C.L. exclusion at 8.6×10^{-47}u2009u2009cm^{2} at 40u2009u2009GeV/c^{2}.

Spin-Dependent Weakly-Interacting-Massive-Particle–Nucleon Cross Section Limits from First Data of PandaX-II Experiment

New constraints are presented on the spin-dependent weakly-interacting-massive-particlex96- (WIMP-)nucleon interaction from the PandaX-II experiment, using a data set corresponding to a total exposure of 3.3×10^{4}u2009u2009kgu2009day. Assuming a standard axial-vector spin-dependent WIMP interaction with ^{129}Xe and ^{131}Xe nuclei, the most stringent upper limits on WIMP-neutron cross sections for WIMPs with masses above 10u2009u2009GeV/c^{2} are set in all dark matter direct detection experiments. The minimum upper limit of 4.1×10^{-41}u2009u2009cm^{2} at 90%xa0confidence level is obtained for a WIMP mass of 40u2009u2009GeV/c^{2}. This represents more than a factor of 2 improvement on the best available limits at this and higher masses. These improved cross-section limits provide more stringent constraints on the effective WIMP-proton and WIMP-neutron couplings.

First dark matter search results from the PandaX-I experiment

We report on the first dark-matter (DM) search results from PandaX-I, a low threshold dual-phase xenon experiment operating at the China JinPing Underground Laboratory. In the 37-kg liquid xenon target with 17.4 live-days of exposure, no DM particle candidate event was found. This result sets a stringent limit for low-mass DM particles and disfavors the interpretation of previously-reported positive experimental results. The minimum upper limit, 3.7 × 10−44 cm2, for the spin-independent isoscalar DM-particle-nucleon scattering cross section is obtained at a DM-particle mass of 49GeV/c2 at 90% confidence level.

Dark Matter Search Results from the Commissioning Run of PandaX-II

We present the results of a search for WIMPs from the commissioning run of the PandaX-II experiment located at the China Jinping underground Laboratory. A WIMP search data set with an exposure of 306

Low-mass dark matter search results from full exposure of the PandaX-I experiment

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Current status of direct dark matter detection experiments

19.1 kg-day was taken, while its dominant

PandaX-III: Searching for neutrinoless double beta decay with high pressure 136 Xe gas time projection chambers

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Dark matter direct search sensitivity of the PandaX-4T experiment

Kr background was used as the electron recoil calibration. No WIMP candidates are identified, and a 90% upper limit is set on the spin-independent elastic WIMP-nucleon cross section with a lowest excluded cross section of 2.97

Limits on Axion Couplings from the First 80 Days of Data of the PandaX-II Experiment

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