Effects of Residue Background Events in Direct Detection Experiments on Determining Properties of Halo Dark Matter

We reexamine the model-independent data analysis methods for extracting properties of Weakly Interacting Massive Particles (WIMPs) by using data (measured recoil energies) from direct Dark Matter detection experiments directly and, as a more realistic study, consider a small fraction of residue background events, which pass all discrimination criteria and then mix with other real WIMP-induced signals in the analyzed data sets. In this talk, the effects of residue backgrounds on the determination of the mass of halo Dark Matter particle as well as on the reconstruction of its one-dimensional velocity distribution function will be discussed.