Search for Neutrinoless Double-Beta Decay of 130Te with CUORE-0

We report the results of a search for neutrinoless double-beta decay in a 9.8 kg yr exposure of ¹³⁰Te using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are 5.1 ±0.3 keV FWHM and 0.058 ±0.004 (stat)±0.002 (syst)counts /(keV kg yr ) , respectively. The median 90% C.L. lower-limit half-life sensitivity of the experiment is 2.9 ×10²⁴ yr and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of ¹³⁰Te and place a Bayesian lower bound on the decay half-life, T₁^{/2 0 ν}>2.7 ×10²⁴ yr at 90% C.L. Combining CUORE-0 data with the 19.75 kg yr exposure of ¹³⁰Te from the Cuoricino experiment we obtain T₁^{/2 0 ν}>4.0 ×10²⁴ yr at 90% C.L. (Bayesian), the most stringent limit to date on this half-life. Using a range of nuclear matrix element estimates we interpret this as a limit on the effective Majorana neutrino mass, m_{β β}<270 - 760 meV .