In April 2015, we reported the results of a search for neutrinoless double beta decay in a 9.8 kg⋅yr exposure of 130Te with CUORE-0. We set a half-life limit of T1∕20ν > 2.7 × 1024 yr at 90% C.L. from CUORE-0 alone, and T1∕20ν > 4.0 × 1024 yr at 90% C.L. when combined with Cuoricino. The background index in the region of interest for this decay was 0.058 ± 0.004 (stat.) ± 0.002 (syst.) counts/(keV⋅kg⋅yr). Shown here is the best-fit model (solid blue line) overlaid on the spectrum of 0νββ decay candidates in CUORE-0 (data points); the data are shown with Gaussian error bars. The peak at 2507 keV is due to 60Co and the dash-dotted line indicates the position at which we expect a potential neutrinoless double beta decay decay signal. The dashed black line indicates the continuum background component in the ROI. The top panel shows the normalized residuals of the best fit model and the binned data points.
