Low-energy signatures in DarkSide-50 experiment and neutrino scattering processes

Dark matter is one of the greatest unsolved mysteries in cosmology nowadays. About 80% of the gravitating matter in the Universe is non-luminous, and its nature and distribution are for the most part unknown. Many experiments around the world and in space are trying to discover dark matter interactions and properties. Among them, the DarkSide project aims to see dark matter signatures inside of time projection chamber filled with liquid argon. In order to reach such a goal, the detector features along with the background must be studied and well understood. This thesis presents the so-called single-electron background of DarkSide-50 experiment, with the perspective of informing the community on the backgrounds which may affect future experiments, especially those looking for low-mass dark matter particles. Another important and irreducible background to be considered in the future regards the coherent neutrino-nucleus scattering in the detector. This process is supposed to mimic in a very similar way the dark matter interaction, making its discovery even harder. For this reason, it is crucial to increase the knowledge of the electroweak and nuclear parameters which are involved in the neutrino scattering process. In this thesis, several phenomenological studies regarding the recent discovery of coherent neutrino-nucleus scattering are presented, along with the determination of quantities accessible through this channel.