Recent results from the MAJORANA DEMONSTRATOR

TL;DR

The MAJORANA DEMONSTRATOR is a low-background, high-resolution experiment designed to search for neutrinoless double-beta decay in germanium-76, demonstrating the feasibility of large-scale, phased experiments with promising initial results.

Contribution

This paper reports on the design, commissioning, and initial results of the MAJORANA DEMONSTRATOR, showcasing its ultra-low background and energy resolution capabilities for neutrinoless double-beta decay searches.

Findings

Achieved record energy resolution for germanium detectors.

Established ultra-low background levels suitable for rare decay searches.

Demonstrated the feasibility of scalable, phased detector deployment.

Abstract

The MAJORANA DEMONSTRATOR is an experiment constructed to search for neutrinoless double-beta decay in $^{76}$Ge and to demonstrate the feasibility to deploy a large-scale experiment in a phased and modular fashion. It consists of two modules of natural and $^{76}$Ge-enriched germanium detectors totalling 44.1 kg, operating at the 4850' level of the Sanford Underground Research Facility in Lead, South Dakota, USA. Commissioning of the experiment began in June 2015, followed by data production with the full detector array in August 2016. The ultra-low background and record energy resolution achieved by the MAJORANA DEMONSTRATOR enable a sensitive neutrinoless double-beta decay search, as well as additional searches for physics beyond the Standard Model. I will discuss the design elements that enable these searches, along with the latest results, focusing on the neutrinoless double-beta decay search. I will also discuss the current status and the future plans of the MAJORANA DEMONSTRATOR, as well as the plans for a future tonne-scale $^{76}$Ge experiment.