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arXiv · 1701.05891

Measurement of the neutrino mixing angle $\theta_{23}$ in NOvA

The NOvA Collaboration·P. Adamson·L. Aliaga·D. Ambrose·N. Anfimov·A. Antoshkin·E. Arrieta-Diaz·K. Augsten·A. Aurisano·C. Backhouse·M. Baird·B. A. Bambah·K. Bays·B. Behera·S. Bending·R. Bernstein·V. Bhatnagar·B. Bhuyan·J. Bian·T. Blackburn·A. Bolshakova·C. Bromberg·J. Brown·G. Brunetti·N. Buchanan·A. Butkevich·V. Bychkov·M. Campbell·E. Catano-Mur·S. Childress·B. C. Choudhary·B. Chowdhury·T. E. Coan·J. A. B. Coelho·M. Colo·J. Cooper·L. Corwin·L. Cremonesi·D. Cronin-Hennessy·G. S. Davies·J. P. Davies·P. F. Derwent·S. Desai·R. Dharmapalan·P. Ding·Z. Djurcic·E. C. Dukes·H. Duyang·S. Edayath·R. Ehrlich·G. J. Feldman·M. Gabrielyan·H. R. Gallagher·S. Germani·T. Ghosh·A. Giri·R. A. Gomes·M. C. Goodman·V. Grichine·R. Group·D. Grover·B. Guo·A. Habig·J. Hartnell·R. Hatcher·A. Hatzikoutelis·K. Heller·A. Himmel·A. Holin·J. Hylen·F. Jediny·M. Judah·G. K. Kafka·D. Kalra·S. M. S. Kasahara·S. Kasetti·R. Keloth·L. Kolupaeva·S. Kotelnikov·I. Kourbanis·A. Kreymer·A. Kumar·S. Kurbanov·K. Lang·W. M. Lee·S. Lin·J. Liu·M. Lokajicek·J. Lozier·S. Luchuk·K. Maan·S. Magill·W. A. Mann·M. L. Marshak·K. Matera·V. Matveev·D. P. Méndez·M. D. Messier·H. Meyer·T. Miao
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Abstract

This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of $6.05\times10^{20}$ protons-on-target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal mixing ($\theta_{23} = \pi/4$). Assuming the normal mass hierarchy, we find $\Delta m^2 = (2.67 \pm 0.11)\times 10^{-3}$ eV$^2$ and $\sin^2 \theta_{23}$ at the two statistically degenerate values $0.404^{+0.030}_{-0.022}$ and $0.624^{+0.022}_{-0.030}$, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6 $\sigma$ significance.

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The NOvA Collaboration, P. Adamson, L. Aliaga, D. Ambrose, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, K. Augsten, A. Aurisano, C. Backhouse, M. Baird, B. A. Bambah, K. Bays, B. Behera, S. Bending, R. Bernstein, V. Bhatnagar, B. Bhuyan, J. Bian, T. Blackburn, A. Bolshakova, C. Bromberg, J. Brown, G. Brunetti, N. Buchanan, A. Butkevich, V. Bychkov, M. Campbell, E. Catano-Mur, S. Childress, B. C. Choudhary, B. Chowdhury, T. E. Coan, J. A. B. Coelho, M. Colo, J. Cooper, L. Corwin, L. Cremonesi, D. Cronin-Hennessy, G. S. Davies, J. P. Davies, P. F. Derwent, S. Desai, R. Dharmapalan, P. Ding, Z. Djurcic, E. C. Dukes, H. Duyang, S. Edayath, R. Ehrlich, G. J. Feldman, M. Gabrielyan, H. R. Gallagher, S. Germani, T. Ghosh, A. Giri, R. A. Gomes, M. C. Goodman, V. Grichine, R. Group, D. Grover, B. Guo, A. Habig, J. Hartnell, R. Hatcher, A. Hatzikoutelis, K. Heller, A. Himmel, A. Holin, J. Hylen, F. Jediny, M. Judah, G. K. Kafka, D. Kalra, S. M. S. Kasahara, S. Kasetti, R. Keloth, L. Kolupaeva, S. Kotelnikov, I. Kourbanis, A. Kreymer, A. Kumar, S. Kurbanov, K. Lang, W. M. Lee, S. Lin, J. Liu, M. Lokajicek, J. Lozier, S. Luchuk, K. Maan, S. Magill, W. A. Mann, M. L. Marshak, K. Matera, V. Matveev, D. P. Méndez, M. D. Messier, H. Meyer, T. Miao. 2017-01-20. Measurement of the neutrino mixing angle $\theta_{23}$ in NOvA. https://doi.org/10.1103/physrevlett.118.151802

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