The NOvA experiment has seen a 4.4σ signal ofν e appearance in a 2 GeVν μ beam at a distance of 810 km. Using 12.33 × 10 20 protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27ν μ →ν e candidates with a background of 10.3 and 102ν μ →ν μ candidates. This new antineutrino data are combined with neutrino data to measure the parameters jΔm 2 32 j ¼ 2.48 þ0.11 −0.06 × 10 −3 eV 2 =c 4 and sin 2 θ 23 in the ranges from (0.53-0.60) and (0.45-0.48) in the normal neutrino mass hierarchy. The data exclude most values near δ CP ¼ π=2 for the inverted mass hierarchy by more than 3σ and favor the normal neutrino mass hierarchy by 1.9σ and θ 23 values in the upper octant by 1.6σ.
We present updated results from the NOvA experiment for ν μ → ν μ and ν μ → ν e oscillations from an exposure of 8.85 × 10 20 protons on target, which represents an increase of 46% compared to our previous publication. The results utilize significant improvements in both the simulations and analysis of the data. A joint fit to the data for ν μ disappearance and ν e appearance gives the best-fit point as normal mass hierarchy, Δm 2 32 ¼ 2.44 × 10 −3 eV 2 =c 4 , sin 2 θ 23 ¼ 0.56, and δ CP ¼ 1.21π. The 68.3% confidence intervals in the normal mass hierarchy are Δm 2 32 ∈ ½2.37; 2.52 × 10 −3 eV 2 =c 4 , sin 2 θ 23 ∈ ½0.43; 0.51 ∪ ½0.52; 0.60, and δ CP ∈ ½0; 0.12π ∪ ½0.91π; 2π. The inverted mass hierarchy is disfavored at the 95% confidence level for all choices of the other oscillation parameters.
The Deep Underground Neutrino Experiment (DUNE) will be a world-class neutrino observatory and nucleon decay detector designed to answer fundamental questions about the nature of elementary particles and their role in the universe.
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