Double-beta decay of to the first excited state of with CUORE-0

We report on a search for double beta decay of to the first excited state of using a exposure of 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: and (). Combining our results with those obtained by the CUORICINO experiment, we achieve the most stringent constraints available for these processes: and ().