Deeper Talks: Final Results From One Decade of Operating the Majorana Demonstrator (Series 10)

Topic: Final Results From One Decade of Operating the Majorana Demonstrator 

The Majorana Demonstrator was built to search for neutrinoless double-beta decay (0νββ) in ⁷⁶Ge. Discovery of 0νββ would prove that the neutrino is its own anti-particle and provide a possible mechanism to explain the excess of matter over anti-matter in the universe. The experiment consists of an array of high purity germanium detectors, constructed using ultra-low background materials at the Davis campus of SURF. The experiment ultimately achieved the best energy resolution and second-lowest background index among 0νββ experiments conducted to date. The Demonstrator took six years of data using detectors isotopically enriched in ⁷⁶Ge, achieving a half-life limit of 8.3×10²⁵ y for 0νββ. The experiment has since continued operation with natural isotopic abundance detectors to perform background studies and search for the decay of ^180mTa, nature’s longest-lived isomeric state. During this time, the Demonstrator has leveraged its unique advantages to search for a variety of rare physics processes, in many cases producing world-leading results. In this talk, I will describe the Majorana Demonstrator and provide a sample of recent physics results.

Speaker: Ian Guinn Oak Ridge National Laboratory 

Ian Guinn is a neutrino physicist at Oak Ridge National Laboratory. He experimentally studies the properties of neutrinos and is interested in the nature of neutrino mass and the origin of matter in the universe. He received his Ph.D. from the University of Washington in 2019, worked as a post-doc at the University of North Carolina at Chapel Hill, and then began at ORNL in 2023. Ian is involved in the search for neutrinoless double-beta decay in germanium detectors, with the Majorana Demonstrator, for which he serves as analysis coordinator, and LEGEND, for which he serves as the pulse-shape analysis lead. Ian spent a great amount of time at SURF between the years of 2014 and 2019, where he helped construct, characterize and operate the Majorana Demonstrator.