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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.