Astroparticle physics experiments study radiation, particles in the cosmos and gravitationalwaves, with experiments in surface, underground, undersea, high-altitude or space laboratories. At the Gran Sasso National Laboratory, the largest underground laboratory with active experiments in the world, state-of-the-art detectors are now operational for the study of dark matter, neutrinos and rare phenomena that can be detected only under the ”cosmic silence” conditions guaranteed by rock protection. Experiments searching for darkmatter candidates employ two different and competing technologies: the Darkside experiment exploits Argon, while the Xenonnt experiment uses Xenon, as the name suggests. Both are dedicated to the direct search for hypothetical dark matter particles called Wimps. A generation of new experiments, including Cupid and Legend, on the other hand, will study neutrinoless double beta decay, an extremely rare phenomenon which, if detected, would mean that neutrino and antineutrino are Majorana particles, i.e. that particle and antiparticle coincide. The environment protected from cosmic ray penetration is also conducive to astrophysical research, such as the study of solar neutrinos and supernova neutrinos. High-energy neutrinos, on the other hand, are studied in submarine experiments such as the large KM3net research infrastructure whose Italian node is located off the coast of Sicily.
Astroparticle physics has also found new applications in different environments: in space, where satellite detectors have direct access to primary cosmic rays that on the Earth’s surface would be attenuated by the atmosphere, with the AMS experiments on the international space station. Among space missions, two telescopes are studying the universe: IXPE observes and measures weak astrophysical sources, such as the clouds ofthe Milky Way, while Euclid, which sent its first and spectacular images in November 2023,will create the largest 3-D cosmic map ever made. In addition, INFN is engaged in major international projects for the study of gamma rays.
Finally, the Italian scientific community plays a cutting-edge role in gravitational wave detection with the development of large interferometric detectors and is involved in the Virgo experiment, the interferometer located at the Ego Observatory in the province of Pisa, as well as in the Einstein Telescope, the future underground observatory for gravitational waves, which Italy is a candidate to host in Sardinia. Gravitational wave research is also being conducted in space with the Lisa project.
