Physics team detects first carbon reaction caused by neutrinos

Scientists from the SNO+ experiment at SNOLAB in Canada have reported the first direct evidence of solar neutrinos interacting with carbon-13 nuclei, transforming them into nitrogen-13. This rare reaction was detected using a 12-meter detector sphere equipped with 9,000 sensors, located 1.24 miles underground to shield from cosmic rays and background noise. By employing a delayed-coincidence technique—observing an initial neutrino-induced flash followed by a secondary flash from nitrogen-13 decay about ten minutes later—the team isolated 5.6 such events over 231 days, closely matching theoretical predictions. This milestone builds on decades of neutrino research, including the original SNO experiment that demonstrated neutrino flavor oscillations and earned a Nobel Prize in 2015. The detection represents the lowest-energy observation of neutrino interactions with carbon-13 nuclei to date and provides the first direct measurement of the reaction’s cross-section to the nitrogen-13 ground state. Researchers emphasize that this achievement not