First measurement of neutrino oscillation parameters using neutrinos and antineutrinos by NOvA

The NOvA experiment has seen a 4.4σ signal of ν_e appearance in a 2 GeV ν_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 27 ν_μ→ν_e candidates with a background of 10.3 and 102 ν_μ→ν_μ candidates. This new antineutrino data are combined with neutrino data to measure the parameters |Δm^2_(32)|=2.48^(+0.11)_(−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) = 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