Abstract
Ge76 can ββ decay into three possible excited states of Se76, with the emission of two or, if the neutrino is Majorana, zero neutrinos. None of these six transitions have yet been observed. The Majorana Demonstrator was designed to study ββ decay of Ge76 using a low background array of high purity germanium detectors. With 98.2 kg-y of isotopic exposure, the demonstrator sets the strongest half-life limits to date for all six transition modes. For 2νββ to the 01+ state of Se76, this search has begun to probe for the first time half-life values predicted using modern many-body nuclear theory techniques, setting a limit of T1/2>1.5×1024 y (90% CL).
| Original language | English |
|---|---|
| Article number | 242501 |
| Journal | Physical Review Letters |
| Volume | 134 |
| Issue number | 24 |
| DOIs | |
| State | Published - Jun 20 2025 |
Funding
This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan . This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contracts and Awards No. DE-AC02-05CH11231, No. DE-AC05-00OR22725, No. DE-AC05-76RL0130, No. DE-FG02-97ER41020, No. DE-FG02-97ER41033, No. DE-FG02-97ER41041, No. DE-SC0012612, No. DE-SC0014445, No. DE-SC0017594, No. DE-SC0018060, No. DE-SC0022339, and No. LANLEM77/LANLEM78. We acknowledge support from the Particle Astrophysics Program and Nuclear Physics Program of the National Science Foundation through Grants No. MRI-0923142, No. PHY-1003399, No. PHY-1102292, No. PHY-1206314, No. PHY-1614611, No. PHY-13407204, No. PHY-1812409, No. PHY-1812356, No. PHY-2111140, and No. PHY-2209530. We gratefully acknowledge the support of the Laboratory Directed Research & Development (LDRD) program at Lawrence Berkeley National Laboratory for this work. We gratefully acknowledge the support of the U.S. Department of Energy through the Los Alamos National Laboratory LDRD Program, the Oak Ridge National Laboratory LDRD Program, and the Pacific Northwest National Laboratory LDRD Program for this work. We gratefully acknowledge the support of the South Dakota Board of Regents Competitive Research Grant. We acknowledge the support of the Natural Sciences and Engineering Research Council of Canada, funding Reference No. SAPIN-2017-00023, and from the Canada Foundation for Innovation John R. Evans Leaders Fund. We acknowledge support from the 2020/2021 L’Oréal-UNESCO for Women in Science Programme. This research used resources provided by the Oak Ridge Leadership Computing Facility at Oak Ridge National Laboratory and by the National Energy Research Scientific Computing Center, a U.S. Department of Energy Office of Science User Facility. We thank our hosts and colleagues at the Sanford Underground Research Facility for their support.