The Neutrino Experiment with a Xenon TPC (NEXT) searches for the neutrinoless double-beta (0 ) decay of 136Xe using high-pressure xenon gas TPCs with electroluminescent amplification. A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of 0 decay better than 1027 years, improving the current limits by at least o...