Dr. Brian Lenardo, Stanford University

"nEXO and the future of neutrinoless double beta decay"

Abstract: The search for neutrinoless double beta decay (0νββ) in atomic nuclei is a powerful probe of new physics. Its observation would be immediate evidence of the Majorana nature of the neutrino, implying the violation of lepton number symmetry and the generation of neutrino masses by a mechanism other than the Higgs. Its discovery may also establish the absolute neutrino mass scale and provide a mechanism for producing the baryon asymmetry observed in the universe today. These exciting possibilities have motivated a worldwide program to search for 0νββ with a variety of isotopes and detection techniques, with the strongest lower limits on the 0νββ half-life currently set at O(10^26) years. In this talk, I will provide an overview of the next generation of experiments, which will be constructed over the next decade and push deep into new parameter space. I will focus in particular on the nEXO experiment, which utilizes the multi-faceted background suppression capabilities of a liquid xenon time projection chamber to achieve a projected half-life sensitivity of 1.35 x 10^28 yrs. I will close with a discussion on long-term possibilities for extending the search for 0νββ to half-lives of O(10^30) years.