Abstrakt
The NOvA experiment has seen a 4.4 sigma signal of (nu) over bar (e) appearance in a 2 GeV (nu) over bar (mu), beam at a distance of 810 km. Using 12.33 x 10(20) protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 (nu) over bar mu -> (nu) over bar (e) candidates with a background of 10.3 and 102 (nu) over bar mu -> (nu) over bar mu candidates.
This new antineutrino data are combined with neutrino data to measure the parameters vertical bar Delta m(32)(2)vertical bar = 2 .48(-0.06)(+0.11) x 10(-3) eV(2)/c(4) and sin(2) theta(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 delta(CP) = pi/2 for the inverted mass hierarchy by more than 3 sigma and favor the normal neutrino mass hierarchy by 1.9 sigma and theta(23) values in the upper octant by 1.6 sigma.