Shedding ‘Nu’ Light on the Nature of Matter: NuDot and the Search for Majorana Neutrinos

Why is the universe dominated by matter, and not antimatter? Neutrinos, with their changing flavors and tiny masses, could provide an answer. If the neutrino is its own antiparticle, it would reveal the origin of the neutrino’s mass, demonstrate that lepton number is not a conserved symmetry of nature, and provide a path to leptogenesis in the early universe. To discover whether this is the case, we must search for neutrinoless double-beta decay.

As the upcoming ton-scale generation of experiments is built, it is key that research and development (R&D) efforts continue to explore how to extend experimental sensitivities to effective Majorana masses beyond 18 meV, corre- sponding to half-lives longer than ∼ 1028 years. These next-next-generation experiments could make a discovery, if neutrinoless double-beta decay is not found at the ton-scale, or offer insight into the mechanism behind lepton num- ber violation, if it is. NuDot is a proof-of-concept liquid scintillator experiment that will explore new techniques for isotope loading and background rejection in future detectors. I’ll discuss the progress we’ve already made in demonstrating how previously-ignored Cherenkov light signals can help us distinguish signal from background, and the technologies we’re developing with an eye towards the coming generations of experiments.