Improved Joint FHC + RHC Sterile Analysis with Nu-on-E Sample

The NOvA experiment measures neutrino oscillations in a nearly pure muon neutrino (antineutrino) beam. The neutral current (NC) and the muon neutrino charged current (CC) interaction disappearance are studied to search for active-to-sterile neutrino oscillations. NOvA consists of two functionally identical detectors placed 14 mrad off-axis of Fermilab's NuMI beamline. The Near Detector (ND) is located 1km from the beam source and 100 m underground on-site at Fermilab, while the Far Detector (FD) sits on the surface 810 km away at Ash River, Minnesota. The NuMI beam is capable of running in forward or reverse horn current modes (FHC/RHC), creating a predominantly neutrino or antineutrino beam, respectively. For this analysis, a simultaneous near and far detector joint fit approach was utilized. Systematic uncertainties constrain the ND, while the statistical uncertainties constrain the FD. For this analysis, we will focus on the FHC, RHC, and a dedicated neutrino-on-electron elastic scattering sample. This interaction is advantageous as it is subject to minimal cross-section uncertainties, which will help reduce degeneracies between other uncertainty categories. In this talk, we will present an update on NOvA's latest sterile neutrino search using 27.2e+20 POT in the FHC mode and 12.5e+20 in the RHC mode.