Improved measurement of neutrino oscillation parameters by the NOvA experiment


We present new νμ → νe, νμ → νμ, ¯νμ → ¯νe, and ¯νμ → ¯νμ 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, ¯νe, and ¯νμ 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 Δm2 32 ¼ ð2.41 0.07Þ × 10−3 eV2 and sin2 θ23 ¼ 0.57þ0.03 −0.04 . The data disfavor combinations of oscillation parameters that give rise to a large asymmetry in the rates of νe and ¯νe appearance. This includes values of the charge parity symmetry (CP) violating phase in the vicinity of δCP ¼ π=2 which are excluded by > 3σ for the inverted mass ordering, and values around δCP ¼ 3π=2 in the normal ordering which are disfavored at 2σ confidence.




ACERO, M. A. et al. Improved measurement of neutrino oscillation parameters by the NOvA experiment. Physical Review D, Washington, v. 106, n. 3, e032004, 2022. DOI: 10.1103/PhysRevD.106.032004. Disponível em: Acesso em: 16 maio 2023.