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

Abstract

We report the results of a search for neutrinoless double-beta decay in a 9.8 kg yr exposure of [superscript 130]Te 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 2.9×10[superscript 24] yr and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of [superscript 130]Te and place a Bayesian lower bound on the decay half-life, T[0ν over 1/2] > 2.7 × 10[superscript 24] yr at 90% C.L. Combining CUORE-0 data with the 19.75 kg yr exposure of [superscript 130]Te from the Cuoricino experiment we obtain T[0ν over 1/2] > 4.0×10[superscript 24] 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[subscript ββ] < 270–760 meV.