We present new νμ→νe, νμ→νμ, ν¯μ→ν¯e, and ν¯μ→ν¯μ oscillation measurements by the NOvA experiment, with a 50% increase in neutrino-mode beam exposure over the previously reported results. The additional data, combined with previously published neutrino and antineutrino data, are all analyzed using improved techniques and simulations. A joint fit to the νe, νμ, ν¯e, and ν¯μ candidate samples within the 3-flavor neutrino oscillation framework continues to yield a best-fit point in the normal mass ordering and the upper octant of the θ23 mixing angle, with Δm322=(2.41±0.07)×10-3 eV2 and sin2θ23=0.57-0.04+0.03. The data disfavor combinations of oscillation parameters that give rise to a large asymmetry in the rates of νe and ν¯e appearance. This includes values of the charge parity symmetry (CP) violating phase in the vicinity of δCP=π/2 which are excluded by >3σ for the inverted mass ordering, and values around δCP=3π/2 in the normal ordering which are disfavored at 2σ confidence.
Bibliographical noteFunding Information:
This document was prepared by the NOvA Collaboration using the resources of the Fermi National Accelerator Laboratory (Fermilab), a U.S. Department of Energy, Office of Science, HEP User Facility. Fermilab is managed by Fermi Research Alliance, LLC (FRA), acting under Contract No. DE-AC02-07CH11359. This work was supported by the U.S. Department of Energy; the U.S. National Science Foundation; the Department of Science and Technology, India; the European Research Council; the MSMT CR, GA UK, Czech Republic; the RAS, RFBR, Russian Ministry of Education and Science (RMES), RSF, and BASIS Foundation, Russia; CNPq and FAPEG, Brazil; STFC, UKRI, and the Royal Society, United Kingdom; and the State and University of Minnesota. We are grateful for the contributions of the staffs of the University of Minnesota at the Ash River Laboratory and of Fermilab.
© 2022 authors. Published by the American Physical Society.