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

TL;DR

This paper presents the initial results from the PandaX-II experiment, which used a large liquid xenon detector to search for WIMP dark matter, setting new upper limits on interaction cross sections but finding no evidence of dark matter.

Contribution

First physics-run data from PandaX-II provides the most stringent limits on WIMP-nucleon interactions in the 3.5 to 1000 GeV/c^2 mass range.

Findings

No dark matter candidates detected above background.

Set upper limit on WIMP-nucleon cross section at 2.5×10⁻⁴⁶ cm² for 40 GeV/c² WIMPs.

Achieved the most stringent constraints to date for certain WIMP masses.

Abstract

We report the WIMP dark matter search results using the first physics-run data of the PandaX-II 500 kg 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$\times10^4$ kg-day,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 3.5 and 1000 GeV/c$^2$. The best upper limit on the scattering cross section is found $2.5\times 10^{-46}$ cm$^2$ for the WIMP mass 40 GeV/c$^2$ at 90% confidence level.