Speaker
Description
Reactor antineutrino experiments enable precision measurements of neutrino oscillation parameters through the observed energy spectrum. The Jiangmen Underground Neutrino Observatory (JUNO) aims to achieve unprecedented precision, requiring tight control of detector-related systematic uncertainties. In the early phase of data taking with limited statistics, accurate normalization—driven primarily by the fiducial volume and target proton number—is particularly important. We present a detailed evaluation of these key normalization uncertainties in JUNO’s first oscillation analysis based on 59.1 days of data collected between August 26 and November 2, 2025. The fiducial volume uncertainty is assessed using multiple vertex reconstruction algorithms, calibration sources, and cosmogenic control samples. The target proton number is determined from precise measurements of the liquid scintillator mass, volume, and hydrogen fraction. These studies demonstrate JUNO’s capability to control key detector-related uncertainties and provide a solid foundation for future high-precision oscillation measurements.