Constraints on Oscillation Parameters from $\hat{I}{½}_e$ Appearance and $\hat{I}{½}_{\hat{I}}¼$ Disappearance in NOvA

Abstract

Results are reported from an improved measurement of $\hat{I}{½}_{\hat{I}}¼\to \hat{I}{½}_e$ transitions by the NOvA experiment. Using an exposure equivalent to $6.05\times 10^{20}$ protons-on-target 33 $\hat{I}{½}_e$ candidates were observed with a background of $8.2\pm 0.8$ (syst.). Combined with the latest NOvA $\hat{I}{½}_{\hat{I}}¼$ disappearance data and external constraints from reactor experiments on ${\sin }^{2}2\hat{I}{¸}_{13}$, the hypothesis of inverted mass hierarchy with $\hat{I}{¸}_{23}$ in the lower octant is disfavored at greater than $93\%$ C.L. for all values of $\hat{I}{´}_{CP}$.

6 pages, 4 figures