Orateur
Description
Neutrinos are among the most abundant particles in the Universe, yet remain some of the least understood. We discovered only recently they have mass, thanks to a phenomenon called “neutrino oscillation”. Neutrinos can exist in different states, called flavors, and each flavor is a combination of different three mass states. One open question concerns the ordering of these mass states. The Jiangmen Underground Neutrino Observatory (JUNO), a 20-kiloton liquid scintillator detector built 650 meters underground in southern China, was designed to answer this question. By detecting antineutrinos emitted by the nearby Taishan and Yangjiang nuclear power plants, JUNO measures a subtle interference pattern in their energy spectrum that encodes which mass ordering nature has chosen. After six years of data taking, three of the key parameters governing neutrino oscillations will be measured with a precision of 0.6% or better, among the most precise ever achieved in this field. This measurement is also expected to reach a significance of ~3σ for the Neutrino mass ordering (NMO).
Reaching this level of precision is as much a statistical challenge as an experimental one. In this contribution, I will present the methodology in the analysis of JUNO's data : a careful treatment of systematic uncertainties and a dedicated statistical techniques that convert the measurements into a mass-ordering significance and reliable confidence intervals.