A Search Of Spin-dependent WIMP-nucleon Interactions Using The PandaⅩ-Ⅱ Detector

One of the most famous story iii physics history is two dark clouds".and this story also inspires generations of physicists to work tirelessly and explore the un-known.Today,although the towering Standard Model(SM)does not seem to break through,but there are more and more discoveries beyond the SM framework,such as neutrinos,dark matter,dark energy,these are currently the forefront of physics.At the same time,human exploration methods are more and more abundant.The dis-covery of gravitational waves has made astronomy enter the era of double messenger.The publication of black hole photos also confirms the enhanceuient of human ob-servation ability.The new super accelerators are also being demonstrated.A lot of evidence from astronomical phenomena to the evolution of the universe makes us believe in the existence of dark matter,and our understanding of the objective world also makes us believe that dark matter is composed of dark matter particles.Weakly Interacting Massive Particles,WIMPs,is one of the most famous candi-date[76].To uncover this new "dark cloud",people have searched for traces of dark matter particles from the sky and the ground.The PandaⅩ project is one of the underground direct detection experiments.The PandaⅩ peoject was initiated by Shanghai Jiaotong University and used liquid xenon as a detection medium.The laboratory is located in the China Jinping underground Laboratory(CJPL),Xichang,Sichuan Province.Currently in progress is the PandaⅩ-Ⅱ experiment of 580kg target xenon,which is one of the largest and most sensitive dark matter direct detection experiments in the world.Yp to now,the experiment has not found any dark matter particles,and the experimental re-sults further compress the possible parameter space.According to the history of rare physical discovery,the breakthrough result is iii the process of insisting on experiment or inadvertent discovery.In terms of liquid xenon dark matter direct detection,increasing the volume and depressing the background are two major di-rections.The PandaⅩ team is upgrading the PandaⅩ-4T experiment with total of 6 tons of liquid xenon and a more rigorous background control.Shandong University has been a member of the PandaX cooperation since 2009.I participated in PandaX project from 2015.At that time.PandaⅩ-Ⅱ building had been completed.In the subsequent tests and operations,I worked as on-site shifter for more than 150 days every year and understanded the detector deeply.I took part in the data analysis work in the PandaX-II experiment,including single-electron signals,detector uniformity correction.detector calibration and so on.As the main author,the work of reaction analysis related to the spin-dependent WIMP-nucleon interactions was completed.The chapters of this paper are arranged as follows:The first chapter is the introduction,which introduces the dark matter experimental group and its progress;the second chapter introduces the nature of liquid xenon as a medium for detectiug dark matter;the third chapter introduces the composition of PandaⅩ-Ⅱ experiment;the fourth chapter introduces The response of the PandaⅩ-Ⅱ experiment to the signal;the fifth chapter introduces the detector calibration:the sixth chapter gives the final analysis and outlook.