Background analysis for charge-current neutrino search with DEAP-3600

DEAP-3600 (Dark matter Experiment using Argon Pulseshape discrimination) is a world-class experiment in the direct detection of dark matter. Dark matter is thought to compose about 27% of the universe, but remains unknown and undetected. The DEAP-3600 Experiment observes light pulses from particle collisions and is located 2 km underground at SNOLAB, the world’s deepest cleanest lab. SNOLAB provides a low-background environment to search for extremely rare physical interactions. In addition to the search for dark matter, DEAP-3600 is attempting the first observation of charged-current solar neutrino interactions in a dark matter detector. Solar neutrinos are elementary particles produced in the fusion reactions which power the Sun. While they are abundant (60 billion neutrinos pass through your thumbnail every second), neutrinos are also weakly interacting. Thus, the detection of charged-current neutrino interactions is an event search, where a handful of events are counted in years of data. To identify these neutrino interactions, the background events must be well understood. Various data cuts are applied to select well-behaved physics events produced by neutrino interactions. If a background event is counted as a neutrino event, the results of the cut-and-count analysis could be affected significantly. I have analyzed the effect of the chosen cut values on the final count of events and explored a specific background population using data cuts. This work has been a critical step in the data analysis for the search of charged-current solar neutrino interactions in the DEAP-3600 detector. The precise detection of this signal could broaden the capabilities of future multi-tonne scale experiments, such as measuring the neutrino spectrum of supernovae and in turn monitoring for supernovae events.