Results from a search for the0 νββ-decay ofTe130

Abstract

A detailed description of the CUORICINO ${}^{130}\mathrm{Te}$ neutrinoless double-beta $(0\hspace{0.5em}\nu \beta \beta )$ decay experiment is given and recent results are reported. CUORICINO is an array of 62 tellurium oxide (${\mathrm{TeO}}_2$) bolometers with an active mass of 40.7 kg. It is cooled to $~8\text{−}10$ mK by a dilution refrigerator shielded from environmental radioactivity and energetic neutrons. It is running in the Laboratori Nazionali del Gran Sasso (LNGS) in Assergi, Italy. These data represent an exposure of 11.83 kg yr or 91 mole-years of ${}^{130}\mathrm{Te}$. No evidence for $0\hspace{0.5em}\nu \beta \beta$-decay was observed and a limit of $T_{1/2}^{0\hspace{0.5em}\nu }({}^{130}\mathrm{Te})⩾3.0\times {10}^{24}\hspace{0.5em}\mathrm{y}$ (90% CL) is set. This corresponds to an upper limit on the effective mass, $\langle m_{\nu }\rangle$, between 0.19 and $0.68$ eV when analyzed with the many published nuclear structure calculations. In the context of these nuclear models, the values fall within the range corresponding to the claim of evidence of $0\hspace{0.5em}\nu \beta \beta$-decay by H. V. Klapdor-Kleingrothaus et al. The experiment continues to acquire data.