SNO+ Detects Solar Neutrinos Turning Carbon-13 Into Nitrogen-13

Researchers observed linked light signals from an initial neutrino hit on carbon‑13 followed minutes later by the decay of nitrogen‑13, confirming the interaction. The analysis covered 231 days of data from May 4, 2022, to June 29, 2023, identifying 5.6 candidate events consistent with 4.7 expected. The measurement provides the lowest‑energy observation of neutrino interactions on carbon‑13 and the first direct cross‑section to the nitrogen‑13 ground state. The SNO+ detector operates two kilometers underground at SNOLAB in Sudbury, Canada, to suppress cosmic‑ray and other background noise. Results are reported in Physical Review Letters and are framed as a foundation for future studies using solar neutrinos to probe rare atomic reactions.