New constraints on oscillation parameters from $\hat{I}{½}_e$ appearance and $\hat{I}{½}_{\hat{I}}¼$ disappearance in the NOvA experiment

Abstract

We present updated results from the NOvA experiment for $\hat{I}{½}_{\hat{I}}¼\to \hat{I}{½}_{\hat{I}}¼$ and $\hat{I}{½}_{\hat{I}}¼\to \hat{I}{½}_e$ oscillations from an exposure of $8.85\times 10^{20}$ protons on target, which represents an increase of 46% compared to our previous publication. The results utilize significant improvements in both the simulations and analysis of the data. A joint fit to the data for $\hat{I}{½}_{\hat{I}}¼$ disappearance and $\hat{I}{½}_e$ appearance gives the best fit point as normal mass hierarchy, $\hat{I}”m_{32}^2=2.44\times 10^{-3}{\mathrm{eV}}^2/c^4$, ${\sin }^2\hat{I}{¸}_{23}=0.56$, and $\hat{I}{´}_{CP}=1.21\ddot{I}€$. The 68.3% confidence intervals in the normal mass hierarchy are $\hat{I}”m_{32}^2\in [2.37,2.52]\times 10^{-3}{\mathrm{eV}}^2/c^4$, ${\sin }^2\hat{I}{¸}_{23}\in [0.43,0.51]\cup [0.52,0.60]$, and $\hat{I}{´}_{CP}\in [0,0.12\ddot{I}€]\cup [0.91\ddot{I}€,2\ddot{I}€]$. The inverted mass hierarchy is disfavored at the 95% confidence level for all choices of the other oscillation parameters.