The next generation neutrinoless double-beta decay experiment nEXO

The nEXO Collaboration is actively engaged in R&D towards a very large detector for neutrinoless double beta decay of $^{136}$Xe. The nEXO detector is rooted in the current EXO-200 program, which has reached a sensitivity for the half-life of the decay of $1.9\times10^{25}$y with an exposure of 100 kg-y. The baseline nEXO design assumes 5 tonnes of liquid xenon, enriched in the mass 136 isotope, within a large monolithic time projection chamber. The sensitivity goal for nEXO is a neutrinoless double-beta decay half-life sensitivity of $1\times10^{28}$y, covering the inverted neutrino mass hierarchy with 5 years of data. We present the conceptual nEXO detector design, the current status of R&D efforts, and the physics case for the experiment.