The CUORE experiment, a ton-scale cryogenic bolometer array, recently began operation at the Laboratori Nazionali del Gran Sasso in Italy. The array represents a significant advancement in this technology, and in this work we apply it for the first time to a high-sensitivity search for a lepton-number-violating process: ${}^{130}\mathrm{Te}$ neutrinoless double-beta decay. Examining a total ${\mathrm{TeO}}_2$ exposure of 86.3 kg yr, characterized by an effective energy resolution of $(7.7\pm 0.5)\mathrm{keV}$ FWHM and a background in the region of interest of $(0.014\pm 0.002)\mathrm{counts}/(\mathrm{keV}\mathrm{kg}\mathrm{yr})$, we find no evidence for neutrinoless double-beta decay. Including systematic uncertainties, we place a lower limit on the decay half-life of $T_{1/2}^{0\nu }({}^{130}\mathrm{Te})>1.3\times {10}^{25}\mathrm{yr}$ (90% C.L.); the median statistical sensitivity of this search is $7.0\times {10}^{24}\mathrm{yr}$. Combining this result with those of two earlier experiments, Cuoricino and CUORE-0, we find $T_{1/2}^{0\nu }({}^{130}\mathrm{Te})>1.5\times {10}^{25}\mathrm{yr}$ (90% C.L.), which is the most stringent limit to date on this decay. Interpreting this result as a limit on the effective Majorana neutrino mass, we find $m_{\beta \beta }<(110-520)\mathrm{meV}$, where the range reflects the nuclear matrix element estimates employed.

We report the results of a search for neutrinoless double-beta decay in a 9.8 kg yr exposure of ${}^{130}\mathrm{Te}$ using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are $5.1\pm 0.3\mathrm{keV}$ FWHM and $0.058\pm 0.004(\text{stat})\pm 0.002(\text{syst})\mathrm{counts}/(\mathrm{keV}\mathrm{kg}\mathrm{yr})$, respectively. The median 90% C.L. lower-limit half-life sensitivity of the experiment is $2.9\times {10}^{24}\mathrm{yr}$ and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of ${}^{130}\mathrm{Te}$ and place a Bayesian lower bound on the decay half-life, $T_{1/2}^{0\nu }>2.7\times {10}^{24}\mathrm{yr}$ at 90% C.L. Combining CUORE-0 data with the 19.75 kg yr exposure of ${}^{130}\mathrm{Te}$ from the Cuoricino experiment we obtain $T_{1/2}^{0\nu }>4.0\times {10}^{24}\mathrm{yr}$ 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, $m_{\beta \beta }<270–760\mathrm{meV}$.

The Cryogenic Underground Observatory for Rare Events (CUORE) is designed to search for neutrinoless double beta decay of $$^{130}$$ Te with an array of 98

Neutrinoless double-beta (0νββ) decay is a hypothesized lepton-number-violating process that offers the only known means of asserting the possible Majorana nature of neutrino mass. The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for 0νββdecay of¹³⁰Te using an array of 988 TeO₂crystal bolometers operated at 10 mK. The detector will contain 206 kg of¹³⁰Te and have an average energy resolution of 5 keV; the projected 0νββdecay half-life sensitivity after five years of livetime is 1.6 × 10²⁶ y at 1σ(9.5 × 10²⁵ y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40–100 meV (50–130 meV). In this paper, we review the experimental techniques used in CUORE as well as its current status and anticipated physics reach.

We report the result of the search for neutrinoless double beta decay of ${}^{82}\mathrm{Se}$ obtained with CUPID-0, the first large array of scintillating $\mathrm{Zn}{}^{82}\mathrm{Se}$ cryogenic calorimeters implementing particle identification. We observe no signal in a 1.83 kg yr ${}^{82}\mathrm{Se}$ exposure, and we set the most stringent lower limit on the $0\nu \beta \beta$ ${}^{82}\mathrm{Se}$ half-life $T_{1/2}^{0\nu }>2.4\times {10}^{24}\mathrm{yr}$ (90% credible interval), which corresponds to an effective Majorana neutrino mass $m_{\beta \beta }<(376–770)\mathrm{meV}$ depending on the nuclear matrix element calculations. The heat-light readout provides a powerful tool for the rejection of $\alpha$ particles and allows us to suppress the background in the region of interest down to $({3.6}_{-1.4}^{+1.9})\times {10}^{-3}\mathrm{counts}/(\mathrm{keV}\mathrm{kg}\mathrm{yr})$, an unprecedented level for this technique.

We report on the measurement of the two-neutrino double-beta decay half-life of $$^{130}$$ Te with the CUORE-0 detector. From an exposure of 33.4