Investigating New Physics Signatures with High-Energy Neutrino Events at NOvA

The NuMI Off-Axis $\nu_e$ Appearance (NOvA) experiment is a long-baseline neutrino oscillation experiment primarily designed to study $\nu_e$, $\Bar{\nu}_e$ appearance as well as $\nu_\mu$ and $\Bar{\nu}_\mu$ disappearance in the energy range of $1<E_\nu < 4$ GeV. Interestingly, the NOvA far detector also records a non-negligible number of high-energy $\nu_e$ and $\Bar{\nu}_e$ events in the extended range of $4<E_\nu<20$ GeV. These events, although sub-dominant in standard oscillation analyses, open a window to probe physics beyond the Standard Model. In this work, we explore the potential of NOvA to constrain new physics scenarios specifically, non-standard neutrino interactions (NSIs) and environmental decoherence, using the high-energy event spectrum observed at the far detector.