Search for Neutrinoless $β^{+}\hspace{-0.2em}EC$ Decay of ${}^{120}$Te with CUORE-0

Abstract

We have performed a search for neutrinoless $β^{+}\hspace{-0.2em}EC$ decay of ${}^{120}$Te using the final CUORE-0 data release. We describe a new analysis method for the simultaneous fit of signatures with different event topology, and of data subsets with different signal efficiency, obtaining a limit on the half-life of the decay of $T_{1/2}>1.6\cdot 10^{21}$ yr at $90\%$ CI. Combining this with results from Cuoricino, a predecessor experiment, we obtain the strongest limit to date, corresponding to $T_{1/2}>2.7\cdot 10^{21}$ yr at $90\%$ CI.

10 pages, 6 figures, 3 tables