Dark Matter Results from 54-Ton-Day Exposure of PandaX-II Experiment.
/ Authors
X. Cui, A. Abdukerim, Wei Chen, Xun Chen, Yunhua Chen, B. Dong, D. Fang, C. Fu, K. Giboni, F. Giuliani
and 46 more authors
L. Gu, Yikun Gu, Xuyuan Guo, Zhifan Guo, K. Han, Changda He, Di Huang, Shengming He, X. Huang, Zhou Huang, X. Ji, Y. Ju, Shaoli Li, Yao Li, Heng Lin, Huaxuan Liu, Jianglai Liu, Yugang Ma, Y. Mao, K. Ni, J. Ning, X. Ren, Fangxia Shi, A. Tan, Cheng Wang, Hong-Wei Wang, Meng Wang, Qiuhong Wang, Siguang Wang, Xiuli Wang, Xuming Wang, Qinyu Wu, Shiyong Wu, M. Xiao, P. Xie, B. Yan, Yong Yang, J. Yue, Dan Zhang, Hongguang Zhang, Tao Zhang, Tianqi Zhang, Li Zhao, Jifang Zhou, N. Zhou, Xiaopeng Zhou
/ Abstract
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} evt/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} kg day, the most stringent upper limit on the spin-independent WIMP-nucleon cross section is set for a WIMP with mass larger than 100 GeV/c^{2}, with the lowest 90% C.L. exclusion at 8.6×10^{-47} cm^{2} at 40 GeV/c^{2}.
Journal: Physical review letters