Joint neutrino oscillation analysis from the T2K and NOvA experiments

Journal Article · Wed Oct 22 00:00:00 UTC 2025 · Nature (London)

DOI: https://doi.org/10.1038/s41586-025-09599-3 · OSTI ID:3013540

Abubakar, S.; Acero, M. A.; Acharya, B.; Adamson, P.; Anfimov, N.; Antoshkin, A.; Arrieta-Diaz, E.; Asquith, L.; Aurisano, A.; Azevedo, D.; Back, A.; Balashov, N.; Baldi, P.; Bambah, B. A.; Bannister, E. F.; Barros, A.; Bat, A.; Bays, K.; Bernstein, R.; Bezerra, T. J. C. ; Bhatnagar, V.; Bhuyan, B.; Bian, J.; Booth, A. C.; Bowles, R.; Brahma, B.; Bromberg, C.; Buchanan, N.; Butkevich, A.; Calvez, S.; Carceller, J. M.; Carroll, T. J.; Catano-Mur, E.; Cesar, J. P.; Chirco, R.; Choudhary, B. C.; Christensen, A.; Cicala, M. F.; Coan, T. E.; Contreras, T.; Cooleybeck, A.; Coveyou, D.; Cremonesi, L.; Davies, G. S.; Derwent, P. F.; Ding, P.; Djurcic, Z.; Dobbs, K.; Dolce, M.; Dueñas Tonguino, D.; Dukes, E. C.; Dye, A.; Ehrlich, R.; Ewart, E.; Filip, P.; Frank, M. J.; Gallagher, H. R.; Giri, A.; Gomes, R. A.; Goodman, M. C.; Group, R.; Habig, A.; Hakl, F.; Hartnell, J.; Hatcher, R.; Hays, J. M.; He, M.; Heller, K.; Hewes, V.; Himmel, A.; Horoho, T.; Ivanova, A.; Jargowsky, B.; Kakorin, I.; Kalitkina, A.; Kaplan, D. M.; Khanam, A.; Kirezli, B.; Kleykamp, J.; Klimov, O.; Koerner, L. W.; Kolupaeva, L.; Kralik, R.; Kumar, A.; Kuruppu, C. D.; Kus, V.; Lackey, T.; Lang, K.; Lasorak, P.; Lesmeister, J.; Lister, A.; Liu, J.; Lock, J. A.; MacMahon, M.; Magill, S.; Mann, W. A.; Manoharan, M. T.; Manrique Plata, M.; Marshak, M. L.; Martinez-Casales, M.; Matveev, V.; Mehta, B.; Messier, M. D.; Meyer, H.; Miao, T.; Miller, W. H.; Mishra, S. R.; Mohanta, R.; Moren, A.; Morozova, A.; Mu, W.; Mualem, L.; Muether, M.; Mulder, K.; Myers, D.; Naples, D.; Nelleri, S.; Nelson, J. K.; Nichol, R.; Niner, E.; Norman, A.; Norrick, A.; Oh, H.; Olshevskiy, A.; Olson, T.; Ozkaynak, M.; Pal, A.; Paley, J.; Panda, L.; Patterson, R. B. ; Pawloski, G.; Petti, R.; Plunkett, R. K.; Porter, J. C. C.; Prais, L. R.; Rafique, A.; Raj, V.; Rajaoalisoa, M.; Ramson, B.; Rebel, B.; Robles, E.; Roy, P.; Samoylov, O.; Sanchez, M. C.; Sánchez Falero, S.; Shanahan, P.; Sharma, P.; Sheshukov, A.; Shmakov, A.; Shorrock, W.; Shukla, S.; Singh, I.; Singh, P.; Singh, V.; Singh Chhibra, S.; Singha, D. K.; Smith, A.; Smolik, J.; Snopok, P.; Solomey, N.; Sousa, A.; Soustruznik, K.; Strait, M.; Suter, L.; Sutton, A.; Swain, S.; Sweeney, C.; Sztuc, A.; Talukdar, N.; Tas, P.; Thakore, T.; Thomas, J.; Tiras, E.; Titus, M.; Torun, Y.; Tran, D.; Trokan-Tenorio, J.; Urheim, J.; Vahle, P.; Vallari, Z.; Vockerodt, K. J.; Waldron, A. V.; Wallbank, M.; Warburton, T. K.; Weber, C.; Wetstein, M.; Whittington, D.; Wickremasinghe, D. A.; Wolcott, J.; Wu, S.; Wu, W.; Wu, W.; Xiao, Y.; Yaeggy, B.; Yahaya, A.; Yankelevich, A.; Yonehara, K.; Zadorozhnyy, S.; Zalesak, J.; Zwaska, R.; Abe, K.; Abe, S.; Adhkary, H.; Akutsu, R.; Alarakia-Charles, H.; Hakim, Y. I. Alj; Monsalve, S. Alonso; Anthony, L.; Aoki, S.; Apte, K. A.; Arai, T.; Arihara, T.; Arimoto, S.; Ashida, Y.; Atkin, E. T.; Babu, N.; Baranov, V.; Barker, G. J.; Barr, G.; Barrow, D.; Bates, P.; Bathe-Peters, L.; Batkiewicz-Kwasniak, M.; Baudis, N.; Berardi, V.; Berns, L.; Bhattacharjee, S.; Blanchet, A.; Blondel, A.; Boistier, P. M. M.; Bolognesi, S.; Bordoni, S.; Boyd, S. B.; Bronner, C.; Bubak, A.; Buizza Avanzini, M.; Caballero, J. A.; Cadoux, F.; Calabria, N. F.; Cao, S.; Cap, S.; Carabadjac, D.; Cartwright, S. L.; Casado, M. P.; Catanesi, M. G.; Chakrani, J.; Chalumeau, A.; Cherdack, D.; Chvirova, A.; Coleman, J.; Collazuol, G.; Cormier, F.; Craplet, A. A. L.; Cudd, A.; D’ago, D.; Dalmazzone, C.; Daret, T.; Dasgupta, P.; Davis, C.; Davydov, Yu. I.; de Perio, P.; De Rosa, G.; Dealtry, T.; Densham, C.; Dergacheva, A.; Dharmapal Banerjee, R.; Di Lodovico, F.; Diaz Lopez, G.; Dolan, S.; Douqa, D.; Doyle, T. A.; Drapier, O.; Duffy, K. E.; Dumarchez, J.; Dunne, P. ; Dygnarowicz, K.; Eguchi, A.; Elias, J.; Emery-Schrenk, S.; Erofeev, G.; Ershova, A.; Eurin, G.; Fedorova, D.; Fedotov, S.; Feltre, M.; Feng, L.; Ferlewicz, D.; Finch, A. J.; Fitton, M. D.; Forza, C.; Friend, M.; Fujii, Y.; Fukuda, Y.; Furui, Y.; García-Marcos, J.; Germer, A. C.; Giannessi, L.; Giganti, C.; Girgus, M.; Glagolev, V.; Gonin, M.; González Jiménez, R.; González Rosa, J.; Goodman, E. A. G.; Gorshanov, K.; Govindaraj, P.; Grassi, M.; Guigue, M.; Guo, F. Y.; Hadley, D. R.; Han, S.; Harris, D. A.; Harris, R. J.; Hasegawa, T.; Hasnip, C. M.; Hassani, S.; Hastings, N. C.; Hayato, Y.; Heitkamp, I.; Henaff, D.; Hino, Y.; Holeczek, J.; Holin, A.; Holvey, T.; Hong Van, N. T.; Honjo, T.; Hooft, M. C. F.; Hosokawa, K.; Hu, J.; Ichikawa, A. K.; Ieki, K.; Ikeda, M.; Ishida, T.; Ishitsuka, M.; Izmaylov, A.; Jachowicz, N.; Jenkins, S. J.; Jesús-Valls, C.; Jia, M.; Jiang, J. J.; Ji, J. Y.; Jones, T. P.; Jonsson, P.; Joshi, S.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kakuno, H.; Kameda, J.; Karpova, S.; Kasturi, V. S.; Kataoka, Y.; Katori, T.; Kawamura, Y.; Kawaue, M.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kikawa, T.; King, S.; Kiseeva, V.; Kisiel, J.; Klustová, A.; Kneale, L.; Kobayashi, H.; Koch, L.; Kodama, S.; Kolupanova, M.; Konaka, A.; Kormos, L. L.; Koshio, Y.; Kowalik, K.; Kudenko, Y.; Kudo, Y.; Kumar Jha, A.; Kurjata, R.; Kurochka, V.; Kutter, T.; Labarga, L.; Lachat, M.; Lachner, K.; Lagoda, J.; Lakshmi, S. M.; Lamers James, M.; Langella, A.; Langridge, D. H.; Laporte, J.-F.; Last, D.; Latham, N.; Laveder, M.; Lavitola, L.; Lawe, M.; Leon Silverio, D.; Levorato, S.; Lewis, S. V.; Li, B.; Lin, C.; Litchfield, R. P.; Liu, S. L.; Li, W.; Longhin, A.; Lopez Moreno, A.; Ludovici, L.; Lu, X.; Lux, T.; Machado, L. N.; Magaletti, L.; Mahn, K.; Mahtani, K. K.; Mandal, M.; Manly, S.; Marino, A. D.; Martin, D. G. R.; Martinez Caicedo, D. A.; Martinez, L.; Martini, M.; Matsubara, T.; Matsumoto, R.; Matveev, V.; Mauger, C.; Mavrokoridis, K.; McCauley, N.; McFarland, K. S.; McGrew, C.; McKean, J.; Mefodiev, A.; Megias, G. D.; Mellet, L.; Metelko, C.; Mezzetto, M.; Miki, S.; Mikola, V.; Miller, E. W.; Minamino, A.; Mineev, O.; Mine, S.; Mirabito, J.; Miura, M.; Moriyama, S.; Moriyama, S.; Morrison, P.; Mueller, Th. A.; Munford, D.; Muñoz, A.; Munteanu, L.; Nagai, Y.; Nakadaira, T.; Nakagiri, K.; Nakahata, M.; Nakajima, Y.; Nakamura, K. D.; Nakano, Y.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Naseby, C. E. R.; Nguyen, D. T.; Nguyen, V. Q.; Niewczas, K.; Nishimori, S.; Nishimura, Y.; Noguchi, Y.; Nosek, T.; Nova, F.; Nugent, J. C.; O’Keeffe, H. M.; O’Sullivan, L.; Okazaki, R.; Okinaga, W.; Okumura, K.; Okusawa, T.; Onda, N.; Ospina, N.; Osu, L.; Oyama, Y.; Paolone, V.; Pasternak, J.; Payne, D.; Peacock, T.; Pfaff, M.; Pickering, L.; Popov, B.; Portocarrero Yrey, A. J.; Posiadala-Zezula, M.; Prabhu, Y. S.; Prasad, H.; Pupilli, F.; Quilain, B.; Quyen, P. T.; Radicioni, E.; Radics, B.; Ramirez, M. A.; Ramsden, R.; Ratoff, P. N.; Reh, M.; Reina, G.; Riccio, C.; Riley, D. W.; Rondio, E.; Roth, S.; Roy, N.; Rubbia, A.; Russo, L.; Rychter, A.; Saenz, W.; Sakashita, K.; Samani, S.; Sánchez, F.; Sandford, E. M.; Sato, Y.; Schefke, T.; Schloesser, C. M.; Scholberg, K.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sekiya, T.; Seppala, D.; Sgalaberna, D.; Shaikhiev, A.; Shiozawa, M.; Shiraishi, Y.; Shvartsman, A.; Skrobova, N.; Skwarczynski, K.; Smyczek, D.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Soler, F. J. P.; Speers, A. J.; Spina, R.; Srivastava, A.; Stowell, P.; Stroke, Y.; Suslov, I. A.; Suzuki, A.; Suzuki, S. Y.; Tada, M.; Tairafune, S.; Takeda, A.; Teklu, A.; Takeuchi, Y.; Tanaka, H. K.; Tanigawa, H.; Tereshchenko, V. V.; Thamm, N.; Touramanis, C.; Tran, N.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vagins, M.; Varghese, M.; Vasilyev, I.; Vasseur, G.; Villa, E.; Virginet, U.; Vladisavljevic, T.; Wachala, T.; Wakabayashi, D.; Wallace, H. T.; Walsh, J. G.; Wan, L.; Wark, D.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilking, M. J.; Wilkinson, C.; Wilson, J. R.; Wood, K.; Wret, C.; Xia, J.; Yamamoto, K.; Yamamoto, T.; Yanagisawa, C.; Yang, Y.; Yano, T.; Yershov, N.; Yevarouskaya, U.; Yokoyama, M.; Yoshimoto, Y.; Yoshimura, N.; Zaki, R.; Zalewska, A.; Zalipska, J.; Zarnecki, G.; Zhang, J.; Zhao, X. Y.; Zheng, H.; Zhong, H.; Zhu, T.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Zsoldos, S.

The landmark discovery that neutrinos have mass and can change type (or flavour) as they propagate—a process called neutrino oscillation—has opened up a rich array of theoretical and experimental questions being actively pursued today. Neutrino oscillation remains the most powerful experimental tool for addressing many of these questions, including whether neutrinos violate charge-parity (CP) symmetry, which has possible connections to the unexplained preponderance of matter over antimatter in the Universe. Oscillation measurements also probe the mass-squared differences between the different neutrino mass states (Δm²), whether there are two light states and a heavier one (normal ordering) or vice versa (inverted ordering), and the structure of neutrino mass and flavour mixing. Here we carry out the first joint analysis of datasets from NOvA and T2K, the two currently operating long-baseline neutrino oscillation experiments (hundreds of kilometres of neutrino travel distance), taking advantage of our complementary experimental designs and setting new constraints on several neutrino sector parameters. This analysis provides new precision on the Δ$$m$$$^{2}_{32}$$ mass difference, finding $2.43$$$$^{+0.04}_{–0.03}$$ x 10^–3 eV² in the normal ordering and $–2.48$$$$^{+0.03}_{–0.04}$$ x 10^–3 eV² in the inverted ordering, as well as a 3σ interval on δ_CP of [−1.38π, 0.30π] in the normal ordering and [−0.92π, −0.04π] in the inverted ordering. The data show no strong preference for either mass ordering, but notably, if inverted ordering were assumed true within the three-flavour mixing model, then our results would provide evidence of CP symmetry violation in the lepton sector.

• Research Organization: Boston Univ., MA (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Florida State University, Tallahassee, FL (United States); State Univ. of New York (SUNY), Stony Brook, NY (United States); Univ. of Colorado, Boulder, CO (United States); Univ. of Pennsylvania, Philadelphia, PA (United States); University of Virginia, Charlottesville, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Contributing Organization: The NOvA Collaboration; The T2K Collaboration
• Grant/Contract Number: 89243024CSC000002; SC0007838; SC0007901; SC0009806; SC0010005; SC0015628; SC0024684
• OSTI ID: 3013540
• Report Number(s): DOE-UVA--07838; FERMILAB-PUB--25-0132-PPD
• Journal Information: Nature (London), Journal Name: Nature (London) Journal Issue: 8086 Vol. 646; ISSN 1476-4687; ISSN 0028-0836
• Publisher: Nature Publishing GroupCopyright Statement
• Country of Publication: United States
• Language: English