Improved Limit on Neutrinoless Double-Beta Decay in Te 130 with CUORE

We report new results from the search for neutrinoless double-beta decay in Te130 with the CUORE detector. This search benefits from a fourfold increase in exposure, lower trigger thresholds, and analysis improvements relative to our previous results. We observe a background of (1.38±0.07)×10-2 counts/(keV kg yr)) in the 0νββ decay region of interest and, with a total exposure of 372.5 kg yr, we attain a median exclusion sensitivity of 1.7×1025 yr. We find no evidence for 0νββ decay and set a 90% credibility interval Bayesian lower limit of 3.2×1025 yr on the Te130 half-life for this process. In the hypothesis that 0νββ decay is mediated by light Majorana neutrinos, this results in an upper limit on the effective Majorana mass of 75-350 meV, depending on the nuclear matrix elements used.