Dark Matter Multi-messenger Indirect Detection And Data Analysis Based On DAMPE Detector

The nature of dark matter particles is one of the most important frontier problems in physics in the 21st century.This paper consists of two main parts on dark matter indirect detection.One is the theoretical study of the indirect detection of dark matter,including the spatial distribution of 7-rays expected in the self-interacting dark matter model for the Galactic GeV excess and the identification a possible dark matter signals in the AMS-02 antiproton data.The second is the research on the data analysis of the DArk Matter Particle Explorer(DAMPE),including resolving the electrons from protons and the Fluka simulation of the detector.In the first chapter,we summarize the basic knowledge and research progress of dark matter.DAMPE,the first Chinese astronomical satellite,is also briefly intro-duced.In the second chapter we search for the signal of dark matter annihilation in the antiproton data of AMS-02.In many theoretical models the annihilation or decay of dark matter particles can produce antiprotons,so the dark matter particle model can be constrained with the cosmic ray antiprotons.There are also background antiprotons in cosmic rays,which are mainly produced by collisions of cosmic ray protons and in-terstellar medium.Their flux can be predicted by cosmic ray propagation model.The latest boron-carbon ratio and the proton spectrum measured by the AMS-02 have pre-cisely constrained the cosmic ray propagation,source injection and solar modulation parameters.Thus we could obtain the reasonable estimation of the background an-tiprotons flux.Comparing with AMS-02 antiproton data,we find that the background model does not fit the data well.And adding a dark matter component can significantly improve the fitting.The mass of the dark matter is about 60-100 GeV,and the velocity-average annihilation cross section is about(1～4)×10-26cm3s-1.These parameters can also be used to explain the Galactic center GeV excess and the faint GeV 7-rays observed in the dwarf spheroidal galaxies Reticulum 2 and Tucana III.Once the result are confirmed by subsequent studies,it will be a breakthrough in the indirect detection of dark matter.In the third chapter,we study the spatial distribution of GeV-γ-rays of self-interacting dark matter model.The Galactic Center GeV excess(GeV excess)dis?covered by the Fermi satellite is a widely concerned potential dark matter signal.A kind of self-interacting dark matter model(SIDM)uses the inverse Compton scattering(ICS)induced by electrons and positrons generated from the dark matter annihilation to explain GeV excess.The SIDM satisfies the resdriction of the AMS-02 electron spectrum and the positron to electron ratio as well.Because of the ICS if induced by positrons and electrons interacting with the Galactic starlight field,it’s possible to explain the fact that most dwarf galaxies do not detect GeV 7-rays excess,for the starlight field and gas density of the dwarf galaxies are very low.We found that the spatial distribution of gamma ray radiation caused by SIDM is of asymmetry,owing to the density of stars and interstellar gas in the Galactic plane are much larger than the outside.We have studied the asymmetry quantitatively,hoping to test it in future experiments.DAMPE is a general purpose high energy cosmic-ray and gamma-ray observatory with very high energy resolution,wide energy range for the electron,gamma-ray and cosmic ray measurements.The DAMPE scientific objectives include the observation of 100GeV～100TeV(proton,nuclide)cosmic rays,10GeV-10TeV gamma-rays and electron cosmic rays.As the energy increases,the electron’s percentage of cosmic rays decreases.Above TeV scale,proton/electron>1000.Therefore,electron/proton resolution of high precision is essential to obtain accurate electron spectra at TeV scale.We use the principal component analysis algorithm(PCA)to find the electron/proton seperation variable efficiently.On the one hand,the PCA method is a unsupervised learning algorithm,which is independent of simulation.The variables obtained reflect the true detector information.On the other hand,the PCA could be helpful to improve the resolution accuracy by using the multidimensional information of the detector.The data analysis of DAMPE depend strongly on the results of simulation and beam test,so simulation of high precision is of great significance for accurate reconstruction.The current simulation is based on the GEANT4 program,which has obvious deficiencies in simulating the interaction of high-energy nuclei.Having constructed priliminary Fluka simulation geometry and data input and output format,we can realize the Fluka simulation of the physical interaction of the DAMPE,and lay a foundation for further analysis of the cosmic ray data.These two aspects are in the fourth and fifth chapter.The last chapter is our summary.