XVIII International Conference on Topics in Astroparticle and Underground Physics (TAUP 2023)

From double to single beta decays – the search for the isomeric decay of 180mTa in the MAJORANA DEMONSTRATOR

29 Aug 2023, 16:15

15m

Hörsaal 7 lecture hall (University of Vienna)

Parallel talk Neutrino physics and astrophysics Dark matter and Neutrino

Speaker

Dr Ralph Massarczyk (Los Alamos National Laboratory)

Description

In 2021, the MAJORANA DEMONSTRATOR experiment ended its search for neutrinoless double beta decay ${}^{76}$Ge. Shown to be one of the world-leading ultra-low-background facilities we modified the experiment to search for one of the rarest isotope decays. The isotope ${}^{180m}$Ta is the only known isotope in nature that occurs in an isomeric state instead of the ground state. The isomeric decay is spin-suppressed, and its decay has never been observed. Beyond understanding the mechanisms that play a role in its decay, the rare state can be exploited to search for dark matter (DM) through a stimulated decay. In this project, we installed clean Ta samples between the Ge detectors, and exploit the ultra-low background underground environment, the high resolution of the MAJORANA detectors, and the well-established analysis routines to search for the nuclear decay and the possible induced emission by DM. In this talk I will present the results from the first year of data taking, and its implications to the dark sector.

This material is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics and Nuclear Physics Programs of the National Science Foundation, and the Sanford Underground Research Facility. We acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program.

Presentation materials

2023_TAUP.pdf