Measurement of reactor neutrino oscillation with the first JUNO data

The Jiangmen Underground Neutrino Observatory (JUNO) released its first high-precision neutrino oscillation parameters on June 10, 2026, as published in Nature. These initial findings significantly improve existing measurements of neutrino oscillation, a fundamental phenomenon in particle physics. The data collected by JUNO demonstrates the observatory's readiness to determine the neutrino mass ordering, a critical question in understanding the fundamental properties of neutrinos. The experiment utilizes a massive 20-kiloton liquid scintillator detector situated 700 meters underground to minimize cosmic ray interference. This depth is crucial for detecting the subtle signals of neutrino interactions. The precision achieved in these early measurements surpasses previous experiments, providing a more refined understanding of how neutrinos change flavor as they travel. The JUNO collaboration, involving over 500 scientists from 15 countries, aims to resolve the ambiguity in the neutrino mass hierarchy, which has implications for cosmology and the search for new physics beyond the Standard Model. The observatory's successful operation and data analysis mark a significant milestone in neutrino physics research.