A Search Of Spin-independent Wimp-Nucleon Interactions Using The PandaX-? And PandaX-? Detectors

Cosmological observations and astrophysical observations have provided strong evidence on the dominating existence of dark matter in the universe.Microscopically,Weakly Interacting Massive Particles?WIMPs?are the most promising elementary particle candidates for dark mat-ter,which naturally link the new physics beyond the Standard Model of particle physics with the observed relic density of the dark matter in the universe.A generic prediction of WIMP theory is that they can interact with normal matter with a weak-scale interaction strength.Such rare interactions can be searched by direct detection experiments,looking for recoils of atomic nuclei by dark matter interaction.Located in the China Jinping Underground Lab?CJPL?,the PandaX?Particle AND Astrophysics experiment with Xenon?experiment utilizes the so-called dual-phase xenon time projection chamber?TPC?to search for WIMPs.This dissertation dis-cusses the WIMP search results from the first and second phases of the PandaX experiment based on data collected from 2014 to 2016,with emphasis on the data analysis.Based on the data,the PandaX has provided a stringent upper limit of spin-independent WIMP-nucleon cross section;the lowest excluded cross section with a 90%cofidence level reaches 2.5×10^-46cm²for a WIMP mass of 40 GeVc^-2.