Measurement of Neutrino Oscillation Parameters at JUNO and Indication of the Neutrino Mass Ordering
Abstract
We report an improved measurement of neutrino oscillation parameters at the Jiangmen Underground Neutrino Observatory (JUNO) and the consequent indication of neutrino mass ordering. The analysis is based on 207.2 live days of data, comprising 8,294 inverse beta-decay candidates collected at an average reactor baseline of 52.5 km. A world-leading precision of approximately 1% was achieved for the atmospheric neutrino mass splitting Δm231, with Δm231=+2.509+0.027−0.025×10−3 eV2 for normal ordering and Δm231=−2.482+0.025−0.026×10−3 eV2 for inverted ordering, using the Daya Bay constraint in the fit to resolve the correct physical minimum under each mass-ordering hypothesis. We further improved the world's most precise measurements of the solar oscillation parameters, obtaining sin2θ12=0.3036±0.0064 and Δm221=(7.388±0.078)×10−5 eV2, corresponding to relative precisions of 2.1% and 1.1%, respectively. Incorporating constraints on Δm231 from long-baseline accelerator neutrino experiments into our analysis favored normal ordering over inverted ordering, with a one-sided significance of at least 2.1σ across all possible CP-violating phases; a Bayesian analysis yielded a Bayes factor of 10.18 in favor of normal ordering.
Related
- Measurement of reactor neutrino oscillation with the first JUNO data
- Quantifying Information Hierarchy for Neutrino Oscillation Parameters at JUNO
- Updated bounds on the (1, 2) neutrino oscillation parameters after first JUNO results
- Indication of Electron Antineutrinos from the Diffuse Supernova Neutrino Background
- A Bayesian approach to the long-baseline neutrino oscillation sensitivity of DUNE
BibTeX
@misc{adam2026measurement,
title = {{Measurement of Neutrino Oscillation Parameters at JUNO and Indication of the Neutrino Mass Ordering}},
author = {Thomas Adam and Timo Ahola and Nurbakyt Amanbek and Fengpeng An and João Pedro Athay de Marcondes de André and Costas Andreopoulos and Giuseppe Andronico and Nikolay Anfimov and Vito Antonelli and Tatiana Antoshkina and Manuel Böhles and Marcel Büchner and Nikita Balashov and Andrea Barresi and Davide Basilico and Eric Baussan and Marco Beretta and Antonio Bergnoli and Nikita Bessonov and Daniel Bick and Lukas Bieger and Svetlana Biktemerova and Thilo Birkenfeld and Simon Blyth and Anastasia Bolshakova and Mathieu Bongrand and Aurélie Bonhomme and Matteo Borghesi and Augusto Brigatti and Riccardo Brugnera and Riccardo Bruno and Jonas Buchholz and Antonio Budano and Jose Busto and Anatael Cabrera and Barbara Caccianiga and Hao Cai and Xiao Cai and Yi-Zhou Cai and Stéphane Callier and Antonio Cammi and Guofu Cao and Jun Cao and Yaoqi Cao and Rossella Caruso and Aurelio Caslini and Cédric Cerna and Vanessa Cerrone and Jinfan Chang and Milo Charavet and Tim Charisse and Chao Chen and Haotian Chen and Jiahui Chen and Jian Chen and Jing Chen and Junyou Chen and Pingping Chen and Shaomin Chen and Shiqiang Chen},
howpublished = {HAL},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.37895},
eprint = {2609.37895},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05781906v1},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Measurement of Neutrino Oscillation Parameters at JUNO and Indication of the Neutrino Mass Ordering
AU - Thomas Adam
AU - Timo Ahola
AU - Nurbakyt Amanbek
AU - Fengpeng An
AU - João Pedro Athay de Marcondes de André
AU - Costas Andreopoulos
AU - Giuseppe Andronico
AU - Nikolay Anfimov
AU - Vito Antonelli
AU - Tatiana Antoshkina
AU - Manuel Böhles
AU - Marcel Büchner
AU - Nikita Balashov
AU - Andrea Barresi
AU - Davide Basilico
AU - Eric Baussan
AU - Marco Beretta
AU - Antonio Bergnoli
AU - Nikita Bessonov
AU - Daniel Bick
AU - Lukas Bieger
AU - Svetlana Biktemerova
AU - Thilo Birkenfeld
AU - Simon Blyth
AU - Anastasia Bolshakova
AU - Mathieu Bongrand
AU - Aurélie Bonhomme
AU - Matteo Borghesi
AU - Augusto Brigatti
AU - Riccardo Brugnera
AU - Riccardo Bruno
AU - Jonas Buchholz
AU - Antonio Budano
AU - Jose Busto
AU - Anatael Cabrera
AU - Barbara Caccianiga
AU - Hao Cai
AU - Xiao Cai
AU - Yi-Zhou Cai
AU - Stéphane Callier
AU - Antonio Cammi
AU - Guofu Cao
AU - Jun Cao
AU - Yaoqi Cao
AU - Rossella Caruso
AU - Aurelio Caslini
AU - Cédric Cerna
AU - Vanessa Cerrone
AU - Jinfan Chang
AU - Milo Charavet
AU - Tim Charisse
AU - Chao Chen
AU - Haotian Chen
AU - Jiahui Chen
AU - Jian Chen
AU - Jing Chen
AU - Junyou Chen
AU - Pingping Chen
AU - Shaomin Chen
AU - Shiqiang Chen
PY - 2026
DA - 2026/09/29
PB - HAL
DO - 10.48550/arxiv.2609.37895
UR - https://hal.science/hal-05781906v1
AB - We report an improved measurement of neutrino oscillation parameters at the Jiangmen Underground Neutrino Observatory (JUNO) and the consequent indication of neutrino mass ordering. The analysis is based on 207.2 live days of data, comprising 8,294 inverse beta-decay candidates collected at an average reactor baseline of 52.5 km. A world-leading precision of approximately 1% was achieved for the atmospheric neutrino mass splitting Δm^2_31, with Δm^2_31=+2.509^+0.027_−0.025×10^−3 eV^2 for normal ordering and Δm^2_31=−2.482^+0.025_−0.026×10^−3 eV^2 for inverted ordering, using the Daya Bay constraint in the fit to resolve the correct physical minimum under each mass-ordering hypothesis. We further improved the world's most precise measurements of the solar oscillation parameters, obtaining sin^2θ_12=0.3036±0.0064 and Δm^2_21=(7.388±0.078)×10^−5 eV^2, corresponding to relative precisions of 2.1% and 1.1%, respectively. Incorporating constraints on Δm^2_31 from long-baseline accelerator neutrino experiments into our analysis favored normal ordering over inverted ordering, with a one-sided significance of at least 2.1σ across all possible CP-violating phases; a Bayesian analysis yielded a Bayes factor of 10.18 in favor of normal ordering.
ER -