CUORE is a ton-scale experiment comprised of 988 TeO2 cryogenic crystals, located at the underground Laboratori Nazionali del Gran Sasso of INFN (Italy). The CUORE detectors are operated as pure calorimeters at a base temperature of ~10 mK, that is reached and maintained thanks to a custom built cryogen-free dilution cryostat designed with the aim of minimizing the vibrational noise and the environmental radioactivity.
In addition to the search for neutrinoless double beta decay of 130-Te, which represents the main physics goal of CUORE, its ultra-low background and large mass make it suitable for the search of other rare processes. One of these is the neutrinoless double beta decay of 128-Te, the second tellurium isotope with the highest natural isotopic abundance (31.75%). The study of this transition is complicated by the high background present in the energy region where the decay peak is expected, namely at (866.7 +/- 0.7) keV. The dominant contribution to this background is due to the 130-Te two-neutrino double beta decay events.
CUORE represents the first experiment able to operate a ton-scale mass of cryogenic TeO2 bolometers in stable conditions, and this allows it to access a factor >10 higher sensitivity to the neutrinoless double beta decay of 128-Te with respect to past direct experiments.