On February 13, 2023, the KM3NeT project recorded an extraordinary event: the detection of a cosmic neutrino with an estimated energy of approximately 220 PeV (220 x 10¹⁵ electronvolts), the highest-energy neutrino ever observed. This result marks a milestone in particle physics and astronomy, opening new perspectives for understanding the universe.
KM3NeT is a cutting-edge research infrastructure located in the depths of the Mediterranean Sea, designed to host next-generation telescopes dedicated to neutrino studies. Once completed, these telescopes will have detection volumes ranging from megatons to several cubic kilometers of crystal-clear seawater. Their location in the deep Mediterranean provides a unique opportunity to observe extreme cosmic phenomena through neutrino detection.
The detection of the 220 PeV neutrino was made possible by ARCA (Astroparticle Research with Cosmics in the Abyss), one of KM3NeT’s main detectors. The event, named KM3-230213A, was identified as a single muon crossing the entire detector, activating over a third of the installed sensors. The inclination of its trajectory, combined with its immense energy, clearly indicates that the muon was generated by the interaction of a cosmic neutrino near the detector.
This success results from international collaboration involving scientific institutions and companies worldwide. Notably, the University of Genoa and the National Institute for Nuclear Physics (INFN) played a crucial role in developing and managing the project. Furthermore, Ligurian companies such as Co.l.Mar contributed by providing essential technologies for the detector’s operation. Co.l.Mar, specializing in marine technologies, designed and produced omnidirectional digital hydrophones, such as the DG1330 model, specifically for the KM3NeT project. These hydrophones were selected by INFN to record acoustic signals at depths of up to 3,500 meters, ensuring unprecedented precision in detecting and locating neutrino events.
The detection of this ultra-high-energy neutrino not only confirms KM3NeT’s capability to observe extreme cosmic phenomena but also opens new avenues for research in astrophysics and particle physics. Understanding the origin and nature of these neutrinos can provide valuable insights into the most energetic processes in the universe, such as those occurring in active galactic nuclei or during supernova explosions.
In conclusion, KM3NeT’s success in detecting the highest-energy neutrino ever observed is a testament to the scientific and technological excellence achieved through international collaboration. The contribution of academic institutions and companies, particularly Ligurian firms like Co.l.Mar, was fundamental in reaching this historic milestone, marking the beginning of a new era in exploring the universe through neutrinos.
