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arXiv · 2505.04469

Measurement of reactor antineutrino oscillation at SNO+

SNO+ Collaboration·:·M. Abreu·V. Albanese·A. Allega·R. Alves·M. R. Anderson·S. Andringa·L. Anselmo·J. Antunes·E. Arushanova·S. Asahi·M. Askins·D. M. Asner·D. J. Auty·A. R. Back·S. Back·A. Bacon·T. Baltazar·F. Barão·Z. Barnard·A. Barr·N. Barros·D. Bartlett·R. Bayes·C. Beaudoin·E. W. Beier·G. Berardi·T. S. Bezerra·A. Bialek·S. D. Biller·E. Blucher·A. Boeltzig·R. Bonventre·M. Boulay·D. Braid·E. Caden·E. J. Callaghan·J. Caravaca·J. Carvalho·L. Cavalli·D. Chauhan·M. Chen·S. Cheng·O. Chkvorets·K. J. Clark·B. Cleveland·C. Connors·D. Cookman·J. Corning·I. T. Coulter·M. A. Cox·D. Cressy·X. Dai·C. Darrach·S. DeGraw·R. Dehghani·J. Deloye·M. M. Depatie·F. Descamps·C. Dima·J. Dittmer·K. H. Dixon·F. Di Lodovico·A. Doxtator·N. Duhaime·F. Duncan·J. Dunger·A. D. Earle·M. S. Esmaeilian·D. Fabris·E. Falk·A. Farrugia·N. Fatemighomi·C. Felber·V. Fischer·E. Fletcher·R. Ford·K. Frankiewicz·N. Gagnon·A. Gaur·J. Gauthier·A. Gibson-Foster·K. Gilje·O. I. González-Reina·D. Gooding·P. Gorel·K. Graham·C. Grant·J. Grove·S. Grullon·E. Guillian·R. L. Hahn·S. Hall·A. L. Hallin·D. Hallman·S. Hans·J. Hartnell·P. Harvey·C. Hearns
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Abstract

The SNO+ collaboration reports its second spectral analysis of reactor antineutrino oscillation using 286 tonne-years of new data. The measured energies of reactor antineutrino candidates were fitted to obtain the second-most precise determination of the neutrino mass-squared difference $\Delta m^2_{21}$ = ($7.96^{+0.48}_{-0.42}$) $\times$ 10$^{-5}$ eV$^2$. Constraining $\Delta m^2_{21}$ and $\sin^2\theta_{12}$ with measurements from long-baseline reactor antineutrino and solar neutrino experiments yields $\Delta m^2_{21}$ = ($7.58^{+0.18}_{-0.17}$) $\times$ 10$^{-5}$ eV$^2$ and $\sin^2\theta_{12} = 0.308 \pm 0.013$. This fit also yields a first measurement of the flux of geoneutrinos in the Western Hemisphere, with $73^{+47}_{-43}$ TNU at SNO+.

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SNO+ Collaboration, :, M. Abreu, V. Albanese, A. Allega, R. Alves, M. R. Anderson, S. Andringa, L. Anselmo, J. Antunes, E. Arushanova, S. Asahi, M. Askins, D. M. Asner, D. J. Auty, A. R. Back, S. Back, A. Bacon, T. Baltazar, F. Barão, Z. Barnard, A. Barr, N. Barros, D. Bartlett, R. Bayes, C. Beaudoin, E. W. Beier, G. Berardi, T. S. Bezerra, A. Bialek, S. D. Biller, E. Blucher, A. Boeltzig, R. Bonventre, M. Boulay, D. Braid, E. Caden, E. J. Callaghan, J. Caravaca, J. Carvalho, L. Cavalli, D. Chauhan, M. Chen, S. Cheng, O. Chkvorets, K. J. Clark, B. Cleveland, C. Connors, D. Cookman, J. Corning, I. T. Coulter, M. A. Cox, D. Cressy, X. Dai, C. Darrach, S. DeGraw, R. Dehghani, J. Deloye, M. M. Depatie, F. Descamps, C. Dima, J. Dittmer, K. H. Dixon, F. Di Lodovico, A. Doxtator, N. Duhaime, F. Duncan, J. Dunger, A. D. Earle, M. S. Esmaeilian, D. Fabris, E. Falk, A. Farrugia, N. Fatemighomi, C. Felber, V. Fischer, E. Fletcher, R. Ford, K. Frankiewicz, N. Gagnon, A. Gaur, J. Gauthier, A. Gibson-Foster, K. Gilje, O. I. González-Reina, D. Gooding, P. Gorel, K. Graham, C. Grant, J. Grove, S. Grullon, E. Guillian, R. L. Hahn, S. Hall, A. L. Hallin, D. Hallman, S. Hans, J. Hartnell, P. Harvey, C. Hearns. 2025-05-07. Measurement of reactor antineutrino oscillation at SNO+. https://doi.org/10.1103/gypt-lc9v

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