Searching for neutrinoless double beta decay using the nEXO detector*

The observation of neutrinoless double-beta decay (0vbb) always implies new physics. The nEXO detector, a 5 ton-scale liquid xenon time projection chamber enriched to 90% in the isotope ¹³⁶Xe, plans to observe this groundbreaking phenomenon, producing first data in 2029. It is a monolithic volume of xenon with many attenuation lengths of radioactive backgrounds between the central region of nEXO and its vessel. The nEXO detector is designed such that no single component dominates its radioactive background, and each low radioactivity material has an identified vendor or source. Its projected sensitivity is robust against backgrounds and “unknown unknowns” due to the use of multiple observables for signal-to-background discrimination, one of which is an order 1% resolution measurement of energy at the 0vbb Q-value. These factors result in an estimated discovery potential for 0vbb at 0.74 x 10²⁸ year half-life at 3σ significance after 10 years. This talk will provide an overview of nEXO as well as a summary of the diverse range of R&D efforts presently underway.