A search for neutrinoless double beta decay of 130Te with a bolometric detector

A thermal detector consisting of a 34 g TeO2 crystal has been operated at about 20 mK in a specially constructed low activity dilution refrigerator installed in the Gran Sasso Underground Laboratory. A spectrum of the thermal pulses collected in more than thousand hours of effective running time shows no evidence for neutrinoless double beta decay of 130Te. The corresponding lower limit on the process lifetime is two orders of magnitude more stringent than those obtained for the same nucleus with counter techniques and of the same order as the values yielded by geochemical searches.