2008-09-05 Results from a search for the 0νββ-decay of 130Te
Results from a search for the 0νββ-decay of Te-130
A detailed description of the CUORICINO 130Te neutrinoless double-beta (0νββ) decay experiment is given and recent results are reported. CUORICINO is an array of 62 tellurium oxide (TeO2) bolometers with an active mass of 40.7 kg. It is cooled to ~8−10 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 130Te. No evidence for 0νββ-decay was observed and a limit of T0ν1/2(130Te) ≥ 3.0 × 1024 y (90% CL) is set. This corresponds to an upper limit on the effective mass, <mν>, 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 0νββ-decay by H. V. Klapdor-Kleingrothaus et al. The experiment continues to acquire data.