Record-Breaking Neutrino Detected by Mediterranean Telescope
PORTOPALO DI CAPO PASSERO, Italy — Researchers at the KM3NeT observatory have detected the most energetic neutrino ever recorded, with an estimated energy of 220 peta-electron-volts (PeV), marking a significant milestone in neutrino astronomy. The event, named KM3-230213A, was registered on February 13, 2023, by the ARCA detector, part of the cubic-kilometer neutrino telescope designed to observe high-energy cosmic events.
This unprecedented detection provides compelling evidence that neutrinos of such extraordinary energies are produced in the universe, reflecting phenomena that are not yet fully understood. The neutrino spurred a muon, which traversed the detector at a shallow angle, indicating its celestial origin, an attribute analyzed meticulously by scientists following the initial detection.
“KM3NeT has begun to probe energy ranges where detected neutrinos may originate from extreme astrophysical phenomena,” said Paschal Coyle, KM3NeT spokesperson. The collaboration also includes researchers from the Center National de la Recherche Scientifique in Marseille, France, who have been integral in bringing this project to fruition.
The muon generated from the neutrino interaction produced detectable signals in over a third of the ARCA’s active sensors, a clear indication of its tremendous energy and trajectory through the detector, which sits approximately 3,450 meters below sea level.
“The unprecedented energy of this neutrino presents exciting possibilities for understanding the forces that shape our universe,” stated Rosa Coniglione, KM3NeT Deputy-Spokesperson, with affiliations to the INFN in Italy. “Neutrinos are unique cosmic messengers that carry information about their sources and the processes occurring deep within cosmic phenomena.”
The KM3NeT observatory, currently under construction, envisions an expansive underwater array of sensors, which utilize Cherenkov light emission from neutral particles in seawater to detect neutrinos and analyze their properties. This innovative technology is pivotal as it allows scientists to explore astrophysical events that were previously beyond reach.
Various cosmic events, such as gamma-ray bursts and supernovae, are expected to generate these high-energy neutrinos. The newly detected KM3-230213A has raised discussions regarding its origin, with potential sources ranging from supermassive black holes to unique interactions involving high-energy cosmic rays and the cosmic microwave background, as astrophysicists look to further understand this unknown territory.
“The analysis required precise calibration and robust algorithms for reconstructing the neutrino’s trajectory and energy,” explained Aart Heijboer, KM3NeT Physics and Software Manager. The current configuration of the ARCA detector was at 10 percent capacity during the event, yet it already exhibited extraordinary sensitivity.
The international collaboration behind this discovery involves over 360 scientists and engineers from 21 countries, showcasing the global effort to unravel the complexities of our universe. As construction continues, updates will enable further detection capabilities for upcoming events, fueling the studies of neutrinos and expanding on foundational understandings of particle physics.
In their published findings in Nature, researchers assert that while the detection of KM3-230213A exemplifies a major advancement, identifying subsequent neutrinos will be vital to building comprehensive models of the universe’s high-energy environments.
