PNNL

Abstract

The Majorana Demonstrator is searching for neutrinoless double-beta decay (0?ßß ) in 7638 Ge 39 using arrays of point-contact germanium detectors operating at the Sanford Underground Research 40 Facility. Background results in the 0?ßß region of interest from data taken during construction, 41 commissioning, and the start of full operations have been recently published. A pulse shape analysis 42 cut applied to achieve this result, named AvsE, is described in this paper. This cut is developed to 43 remove events whose waveforms are typical of multi-site energy deposits while retaining (903.5)% 44 of single-site events. This pulse shape discrimination is based on the relationship between the maxi- mum current and energy, and tuned using 22845. The calibration source data. The efficiency uncertainty 46 accounts for variation across detectors, energy, and time, as well as for the position distribution 47 difference between calibration and 0?ßß events, established using simulations.