Two-Detector Search for 3+1 Active-to-Sterile Neutrino Oscillations in NOvA

NOvA is a long-baseline neutrino experiment optimised for studying neutrino oscillations in the NuMI beam. The experiment consists of two functionally identical liquid scintillator detectors at baselines of 1km and 810km, with the latter placed 14.6 mrad from the beam’s central axis.This poster presents a search for 3+1 sterile neutrino oscillations in neutrino beam using $11.0 times 10^{20}$ protons on target (POT) in the near detector and $13.6 times 10^{20}$ POT in the far detector.

This analysis utilises charged current $nu_{mu}$ and neutral current selections to probe the $nu_{mu} rightarrow nu_{mu}$ and active $rightarrow$ sterile oscillation probabilities respectively to place constraints on the $Delta m_{41}^{2}$, $theta_{24}$ and $theta_{34}$ mixing parameters.

Unlike previous sterile searches from NOvA, this analysis utilises a two-detector fit approach with a Gaussian multivariate treatment of systematic uncertainties and a Poisson likelihood treatment of statistical uncertainties. As this approach is robust against oscillations in the near detector, results will be presented including 90% CL limits over a broad range in $Delta m_{41}^{2}.