Short-Baseline Sterile-Neutrinos Search with the NOvA ND

The NOvA (NuMI Off-Axis electron-neutrino Appearance) experiment is a long-baseline accelerator neutrino experiment at Fermilab, comprising a ~300-ton Near Detector (ND) ~1 km from the beam source and a 14-kton Far Detector (FD) in Ash River, Minnesota, 810 km away. Both detectors are ~14 mrad off-axis from the neutrino beam. NOvA’s primary goals are to determine the neutrino mass ordering, make precise measurements of mixing parameters, and probe potential CP violation in the lepton sector via (anti)neutrino oscillations. In addition, NOvA pursues searches beyond the three-flavor framework, including non-standard interactions (NSI) and sterile-neutrino scenarios.

This talk will present the current status of a short-baseline sterile-neutrino search with the NOvA ND in a (3+1) framework, using combined neutrino (FHC) and antineutrino (RHC) datasets. We construct oscillatable spectra for muon (anti)neutrinos disappearance and electron (anti)neutrino​ appearance with updated selections and a unified constraint strategy. Our ongoing combined neutrino/antineutrino fit scans the mass-splitting parameter (Delta m 41 squared) over the range from one-hundredth to one-hundred electronvolt-squared—final bounds to be set after reconstruction and systematics validation—to probe the muon-to-electron neutrino appearance amplitude and the mixing angles theta-14 and theta-24.