Sensitivity of NEXT-100 to neutrinoless double beta decay

[EN] NEXT-100 is an electroluminescent high-pressure xenon gas time projection chamber that will search for the neutrinoless double beta (0¿ßß) decay of 136Xe. The detector possesses two features of great value for 0¿ßß searches: energy resolution better than 1% FWHM at the Q value of 136Xe and track reconstruction for the discrimination of signal and background events. This combination results in excellent sensitivity, as discussed in this paper. Material-screening measurements and a detailed Monte Carlo detector simulation predict a background rate for NEXT-100 of at most 4 × 10¿4 counts keV¿1 kg¿1 yr¿1. Accordingly, the detector will reach a sensitivity to the 0¿ßß-decay half-life of 2.8 × 1025 years (90% CL) for an exposure of 100 kg·year, or 6.0 × 1025 years after a run of 3 effective years. The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the Ministerio de Econom¿ıa y Competitividad of Spain under grants CONSOLIDERIngenio 2010 CSD2008-0037 (CUP), FIS2014-53371-C04 and the Severo Ochoa Program SEV-2014-0398; the Portuguese FCT and FEDER through the program COMPETE, project PTDC/FIS/103860/2008; the U.S. Department of Energy under contracts number DE-AC02-07CH11359 (Fermi National Accelerator Laboratory) and DE-FG02-13ER42020 (Texas A&M); and the University of Texas at Arlington. We thank Joshua B. Albert for useful discussions regarding the cosmogenic backgrounds. Martín-Albo, J.; Muñoz Vidal, J.; Ferrario, P.; Nebot-Guinot, M.; Gomez-Cadenas, JJ.; Álvarez-Puerta, V.; Azevedo, C... (2016). Sensitivity of NEXT-100 to neutrinoless double beta decay. Journal of High Energy Physics. (5). https://doi.org/10.1007/JHEP05(2016)159 S. Weinberg, Baryon and Lepton Nonconserving Processes, Phys. Rev. Lett. 43 (1979) 1566 [ INSPIRE ]. P. Minkowski, μ → eγ at a Rate of One Out of 109 Muon Decays?, Phys. Lett. B 67 (1977) 421 [ INSPIRE ]. M. Gell-Mann, P. Ramond and R. Slansky, Complex spinors and unified theories, in Supergravity, P. van Nieuwenhuizen and D.Z. Freedman eds., North-Holland Publishing Company, Amsterdam The Netherlands (1979), pg. 315. T. Yanagida, Horizontal symmetry and masses of neutrinos, in Proceedings of the Workshop on the Unified Theories and the Baryon Number in the Universe, O. Sawada and A. Sugamoto eds., KEK, Tsukuba Japan (1979), pg. 95. R.N. Mohapatra and G. Senjanović, Neutrino Mass and Spontaneous Parity Violation, Phys.