Physical Review Letters
We report results from the first search for nu(mu) -> nu(e) transitions by the NOvA experiment. In an exposure equivalent to 2.74 x 10(20) protons on target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of 0.99 +/- 0.11 (syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07 +/- 0.14 (syst). The 3.3 sigma excess of events observed in the primary analysis disfavors 0.1 pi < delta(CP) < 0.5 pi in the inverted mass hierarchy at the 90% C.L.
Adamson, P., Ader, C., Andrews, M., Anfimov, N., Anghel, I., Arms, K., ... & Baird, M. (2016). First measurement of electron neutrino appearance in NOvA. Physical review letters, 116(15), 151806.