
On April 6th 2022, the new results of the CUORE (Cryogenic Underground Observatory for Rare Events) experiment, located at the Gran Sasso National Laboratories of the National Institute of Nuclear Physics (INFN), were published on Nature.
For some years, about 1027 nuclei of 130Te have been permanently kept under observation, at a temperature of only 10 mK. If the neutrino were of "Majorana" type, they should be able to decay creating matter (a pair of electrons) but no antimatter. In support of the strong dominance of matter in our Universe. The data processed so far are equivalent to 1 year of observation of 1 ton of tellurite: an excellent figure for this type of experiments. For the moment the event sought has not been identified, but the search continues.
The experiment was conceived 25 years ago by Professor Ettore Fiorini, professor emeritus of our University, to crown the pioneering studies on cryogenic detectors conducted in the 90s of the last century by his Milanese research group, which included our colleagues Chiara Brofferio, Angelo Nucciotti, Maura Pavan, Ezio Previtali.
“The result of this experiment has an important impact on astroparticle physics, in particular as regards the neutrino, and in low temperature technology, with a cryostat capable of keeping more than 1500 kg cold for years, between detector and ancillary material, at temperatures close to absolute zero", explains Professor Chiara Brofferio, Italian spokesperson of the experiment. And she adds: “Professor Fiorini's group, of which I was a part, guided this adventure from the very beginning. Today we are proud to reap the benefits”.
CUORE is run by an international research collaboration, led by INFN in Italy and Berkeley National Laboratory in the United States. The University of Milan-Bicocca has always contributed to it with a large number of physicists and students.
In the photo: The installation in the cryostat of the "towers" that make up the detector (Credit: Yury Suvorov and the CUORE Collaboration)