A Search for Double Beta Decay of ¹²⁸ Te and ¹³⁰ Te Leading to the First Excited State of Daughter Nuclei

A shielded Ge(Li) surrounded by natural tellurium and located in an underground laboratory has been used to search for double beta decay of 128 Te and 130 Te leading to the first 2 + excited state of the corresponding Xenon isotopes. No evidence for such decays is found and it is proved experimentally that the geologically measured rate for double beta decay of 130 Te is dominated by the 0 + -0 + mechanism. Upper limits on the presence of right-handed currents are obtained which are independent of the value for the neutrino mass.