The Majorana experiment: an ultra-low background search for neutrinoless double-beta decay

TL;DR

The Majorana experiment aims to detect neutrinoless double-beta decay using ultra-low background germanium detectors, which could reveal the Majorana nature of neutrinos and inform their mass scale.

Contribution

It introduces the Demonstrator setup as a prototype to evaluate background levels for a future large-scale neutrinoless double-beta decay search.

Findings

Design of an ultra-low background germanium detector setup

Projected background rate of one count per tonne-year

Feasibility of scaling to a 1-tonne experiment

Abstract

The observation of neutrinoless double-beta decay would resolve the Majorana nature of the neutrino and could provide information on the absolute scale of the neutrino mass. The initial phase of the Majorana experiment, known as the Demonstrator, will house 40 kg of Ge in an ultra-low background shielded environment at the 4850' level of the Sanford Underground Laboratory in Lead, SD. The objective of the Demonstrator is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a narrow region of interest around the 76Ge neutrinoless double-beta decay peak.