Speaker: Vince Guiseppe (USD)

Titlte: Investigation of Backgrounds to Rare Event Searches Deep Underground

Abstract:
Planned and future underground physics experiments aim to unravel some of the deepest mysteries of the universe including the nature of neutrinos, the matter/antimatter asymmetry, the existence of dark matter, proton decay and stellar evolution. To address these questions, large particle detectors must be built deep underground to provide shielding from cosmic radiation found on the Earth’s surface. In addition to the reduction in cosmic radiation, all other sources of background radiation must be suppressed to unprecedented levels to provide the needed experimental sensitivities. Neutrinoless double-beta decay experiments, such as the Majorana Experiment, are being built underground to determine the nature of neutrinos, the existence of a lepton violating process, and the effective Majorana neutrino mass. These experiments rely on low levels of radioactive backgrounds and a thorough understanding of existing and potentially new backgrounds. Often, potential rare backgrounds are unmeasured and their rates unkown. Results and findings from investigations into problematic neutron-induced and radon-generated backgrounds will be presented along with their effect on a Majorana-like experiment.