In an underground laboratory deep beneath a mountain in Central Italy, an array of crystals, chilled to within a hair of absolute zero – the coldest possible temperature in the universe – has been steadily compiling one of the most precise measurements to date in pursuit of a rare particle process. If it is proven to exist, this process may well be the “smoking gun” of how matter was created in the universe.

The experiment that is designed to seek out this process, called CUORE (Cryogenic Underground Observatory for Rare Events), is at Gran Sasso National Laboratories, part of the Italian National Institute for Nuclear Physics (INFN).