Double-beta decay of $$^{130}\hbox {Te}$$130Te to the first $$0^+$$0+ excited state of $$^{130}\hbox {Xe}$$130Xe with CUORE-0

Abstract We report on a search for double beta decay of $$^{130}\hbox {Te}$$130Te to the first $$0^{+}$$0+ excited state of $$^{130}\hbox {Xe}$$130Xe using a $$9.8\,\hbox {kg}\cdot \hbox {yr}$$9.8kg·yr exposure of $$^{130}\hbox {Te}$$130Te collected with the CUORE-0 experiment. In this work we exploit different topologies of coincident events to search for both the neutrinoless and two-neutrino double beta decay modes. We find no evidence for either mode and place lower bounds on the half-lives: $$T^{0\nu }_{0^+_1}>7.9\cdot 10^{23}\hbox {yr}$$T01+0ν>7.9·1023yr and $$T^{2\nu }_{0^+_1}>2.4\cdot 10^{23}\hbox {yr}$$T01+2ν>2.4·1023yr ($$90\%\,\hbox {CL}$$90%CL). Combining our results with those obtained by the CUORICINO experiment, we achieve the most stringent constraints available for these processes: $$T^{0\nu }_{0^+_1}>1.4\cdot 10^{24}\hbox {yr}$$T01+0ν>1.4·1024yr and $$T^{2\nu }_{0^+_1}>2.5\cdot 10^{23}\hbox {yr}$$T01+2ν>2.5·1023yr ($$90\%\,\hbox {CL}$$90%CL)