Measurement of reactor antineutrino oscillations with 1.46 ktonne-years of data at SNO+
hep-ex
/ Authors
M. Abreu, A. Allega, M. R. Anderson, S. Andringa, D. M. Asner, D. J. Auty, A. Bacon, T. Baltazar, F. Barão, N. Barros
and 101 more authors
R. Bayes, E. W. Beier, A. Bialek, S. D. Biller, E. Caden, M. Chen, S. Cheng, B. Cleveland, D. Cookman, J. Corning, S. DeGraw, R. Dehghani, J. Deloye, M. M. Depatie, C. Dima, J. Dittmer, K. H. Dixon, M. S. Esmaeilian, E. Falk, N. Fatemighomi, R. Ford, S. Gadamsetty, A. Gaur, D. Gooding
/ Abstract
The SNO+ Collaboration reports new results on reactor antineutrino oscillations using data acquired from May 2022 through July 2025. The spectral analysis of a flux dominated by nuclear reactors at 240, 350, and 355 kilometers yields the mass-squared difference $Δm^2_{21}=(7.93^{+0.21}_{-0.24})\times 10^{-5}$ eV$^2$. This result is compatible with and approaches the precision of the only other long-baseline reactor antineutrino measurement, by KamLAND. Combining these measurements, along with those from solar neutrino experiments, the global values of the neutrino mixing parameters become: $Δm^2_{21}$ = $(7.63\pm0.17)\times 10^{-5}$ eV$^2$ and $\sin^2{θ_{12}}=0.310\pm0.012$. The analysis of geoneutrinos at SNO+ is also improved, with a measured signal of 49$^{+13}_{-12}$ TNU.