UNC-CH Physics and Astronomy Preliminary Exam
Anna Reine
“Study of Backgrounds in the MAJORANA DEMONSTRATOR through Analysis of Coincidence Data”
The MAJORANA DEMONSTRATOR is a germanium-based neutrinoless double beta decay search (0???) located in the Sanford Underground Research Facility. In its lowest background configuration, the DEMONSTRATOR has achieved a background level of 11.9 ± 2.0 cnts/(FWHM t yr), one of the lowest backgrounds of all 0??? experiments. Understanding the sources of DEMONSTRATOR backgrounds is essential to designing a tonne-scale neutrinoless double beta decay experiment with reduced backgrounds in order to cover the half life range associated with the inverted neutrino mass ordering.
The decay chains of naturally-occurring 238U and 232Th include a number of fast decays or de-excitations that can result in coincident or near-coincident energy deposits in the DEMONSTRATOR’s detector array. Comparisons of coincident events between simulations and experimental data can provide information about the location of radioactive contaminants. I will discuss the tools I have been developing to conduct this analysis, my plans for applying these tools to a number of different decays, and the relationship between my analysis and other methods of studying backgrounds.