Measurement of neutrino and antineutrino oscillations by the T2K experiment including a new additional sample of nu(e) interactions at the far detector



Abe, K, Amey, J, Andreopoulos, C ORCID: 0000-0003-2020-8215, Antonova, M, Aoki, S, Ariga, A, Ashida, Y, Ban, S, Barbi, M, Barker, GJ
et al (show 286 more authors) (2017) Measurement of neutrino and antineutrino oscillations by the T2K experiment including a new additional sample of nu(e) interactions at the far detector. Physical Review D: Particles, Fields, Gravitation and Cosmology, 96 (9).

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Abstract

The T2K experiment reports an updated analysis of neutrino and antineutrino oscillations in appearance and disappearance channels. A sample of electron neutrino candidates at Super-Kamiokande in which a pion decay has been tagged is added to the four single-ring samples used in previous T2K oscillation analyses. Through combined analyses of these five samples, simultaneous measurements of four oscillation parameters, | Δ m 2 32 | , sin 2 θ 23 , sin 2 θ 13 , and δ CP and of the mass ordering are made. A set of studies of simulated data indicates that the sensitivity to the oscillation parameters is not limited by neutrino interaction model uncertainty. Multiple oscillation analyses are performed, and frequentist and Bayesian intervals are presented for combinations of the oscillation parameters with and without the inclusion of reactor constraints on sin 2 θ 13 . When combined with reactor measurements, the hypothesis of C P conservation ( δ CP = 0 or π ) is excluded at 90% confidence level. The 90% confidence region for δ CP is [ − 2.95 , − 0.44 ] ( [ − 1.47 , − 1.27 ] ) for normal (inverted) ordering. The central values and 68% confidence intervals for the other oscillation parameters for normal (inverted) ordering are Δ m 2 32 = 2.54 ± 0.08 ( 2.51 ± 0.08 ) × 10 − 3     eV 2 / c 4 and sin 2 θ 23 = 0.5 5 + 0.05 − 0.09 ( 0.5 5 + 0.05 − 0.08 ), compatible with maximal mixing. In the Bayesian analysis, the data weakly prefer normal ordering (Bayes factor 3.7) and the upper octant for sin 2 θ 23 (Bayes factor 2.4).

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 05 Jan 2018 14:31
Last Modified: 22 Jan 2021 16:10
DOI: 10.1103/PhysRevD.96.092006
Open Access URL: https://journals.aps.org/prd/abstract/10.1103/Phys...
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3015478