UNC-CH PHYSICS AND ASTRONOMY DISSERTATION DEFENSE
Kris Vorren, UNC-CH
“A Direct Search for Dark Matter with the MAJORANA DEMONSTRATOR”
The MAJORANA DEMONSTRATOR is a neutrinoless double-beta decay experiment currently operating 4850 ft underground in the Sanford Underground Research Facility in Lead, SD. Sub-keV thresholds and excellent low-energy resolution are features of the p-type point contact high-purity germanium detectors deployed by MAJORANA, making them ideal for use in direct dark matter searches when combined with MAJORANA’s ultra-low backgrounds. An analysis of data from a 2015 commissioning run of the DEMONSTRATOR with 478 kg d of exposure was performed to search for mono-energetic lines in the detectors’ energy-spectrum from bosonic dark matter absorption. No dark matter signature was found in the 5-100 keV range, and upper limits were placed on dark bosonic pseudoscalar and vector-electric couplings. The same analysis produced null results and upper limits for three additional rare-event searches: Pauli-Exclusion Principle violating decay, solar axions, and electron decay. Improvements made to MAJORANA since commissioning will result in increased sensitivity to rare-event searches in future analyses.