The NEXT-100 Neutrinoless Double Beta Decay Experiment

The NEXT experiment is searching for Majorana neutrinos through the signature of neutrinoless double beta decay ($0 \nu \beta \beta$). Detection of this process would indicate that, unlike all other fundamental fermions, the neutrino is its own antiparticle, has a Majorana mass term, and lepton number is not conserved. In order to search for this process, NEXT utilizes an electroluminescent high pressure gaseous $^{136}$Xe time projection chamber (HPGXeTPC). This technology gives NEXT several key advantages, including excellent energy resolution ($\textless$ 1\% FWHM at the decay energy), and background rejection through track topology. The 100 kg NEXT-100 detector is under construction with installation and commissioning planned for late 2021. NEXT-100 is expected to reach a sensitivity of $2.8 \times 10^{25}$ years (90\% CL) for an exposure of 100 kg-year, or $6.0 \times 10^{25}$ years after an effective three years run time. We will discuss both the basic design and physics of the NEXT-100 detector.