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PandaX-4T is not just a dark matter detector, as you may be more familiar with. For such a large and exquisite detector, we can explore multiple physics topics. Neutrino physics is one such important direction.

Background neutrinos can elastically scatter with target nucleus (coherently elastic neutrino-nucleus scattering or CEvNS), producing nuclear recoil signals in a dark matter detector that can mimic dark matter signals. This intrinsic background is the so-called “neutrino floor”, which will ultimately limit the sensitivity of dark matter direct detection. On the other hand, it also provides very interesting physics opportunities to study neutrino interactions.

With the extra energy gained from the cosmic rays, sub-GeV dark matter particles can produce visible recoil signals in the detector. We present a new result searching for the cosmic ray boosted dark matter (CRDM) with the PandaX-II full data. This work is motivated by the theoretical paper (PRL. 126 091804), which first pointed out that a sidereal diurnal modulation in signal rate and energy spectrum due to the Earth shielding is expected for low mass CRDM.

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On December 24, 2021, the first dark matter search result from PandaX-4T, a liquid xenon detection experiment, was published in Physical Review Letters as the "Editor's Suggestion" [1]. The American Physical Society 《Physics》 reported this PandaX-4T latest result together with another result from the Axion Dark Matter Experiment with a title of "Tightening the Net on Two Kinds of Dark Matter"

A new result on searching of light dark matter (DM) with PandaX-II experimental data was published online in Physical Review Letters on May 28, 2021 with a title of "Search for Light Dark Matter–Electron Scattering in the PandaX-II Experiment "[1]. This is the 6th PRL paper published with PandaX-II data.

The PandaX-II experiment is completed and the PandaX-4T experiment is under installation. The future PandaX program will focus on the following two main directions:

  1. Develop PandaX-4T into a multi-purpose liquid xenon experiment, to push further the dark matter search and other physics topics;
  2. Develop and operate a 100-kg high pressure gas TPC (HpgTPC), PandaX-III, as a pathfinder for a tracking calorimeter to search for $0\nu\beta\beta$ in ${}^{136}Xe$.

Hello 2021!

The full International Advisory Committee 2020 Report.
The PandaX collaboration released the latest results on the search of WIMPs and axions based on the full exposure of data at the International High Energy Physics Conference (ichep2020) on July 30, 2020. Detailed analyses were reported with an online seminar on August 20. The most stringent constraint is set for WIMPs around 10 GeV/c2 using the nuclear recoil events. The intriguing electron recoil event excess observed by XENON1T [1] was tested with the electron recoil data, and was found to be within the constraint of the PandaX-II data.

The PandaX-II collaboration released the official WIMP search results using 54 ton-day exposure on Aug. 23, 2017. No excess events were found above the expected background. The most stringent upper limit on spin-independent WIMP-nucleon cross section was set for a WIMP mass greater than $100 GeV/c^{2}$, with the lowest exclusion at $8.6\times10^{-47} cm^{2}$ at $40 GeV/c^{2}$. The result reported here is more conservative than the preliminary result shown during the TeVPA2017 conference, due to the adoption of updated photon/electron detection efficiencies.