Sensitivity of Liquid Xenon Detectors for Low Mass Dark Matter

Dark matter direct detection experiments based on liquid xenon detectors are one of the most promising strategies to determine the nature of dark matter. In this thesis, we discuss the sensitivity of such detectors for nuclear recoils with energy below 10 keV corresponding to dark matter particles with a mass of less than 10 GeV. The interest in low mass dark matter has been roused by the claimed observation of a corresponding signal in the experiments DAMA and CoGeNT. We demonstrate that liquid xenon detectors like XENON100 should also be able to observe such low mass dark matter particles and can consequently settle the present discussion. First, we discuss the detector resolution and determine the acceptance of liquid xenon detectors in the low energy region. Next, we analyze the production and detection of scintillation light in liquid xenon, calculating the relative scintillation efficiency. Moreover, we perform Monte Carlo simulations to predict the light collection efficiency for a given detector. Finally, we discuss the phenomenology of direct detection for fermionic dark matter. We calculate the cross sections for the interaction between dark matter and nuclei in different models and give the corresponding exclusion limits of recent experiments