Probing new physics scenarios using high energy events at NOvA far detector

TL;DR

This paper explores how high energy events at the NOvA neutrino experiment can be used to probe new physics scenarios like non-standard interactions and environmental decoherence, improving constraints and resolving parameter degeneracies.

Contribution

It demonstrates the potential of high energy neutrino events at NOvA to constrain non-standard interaction parameters and environmental decoherence, enhancing sensitivity beyond previous analyses.

Findings

Including high energy events removes degeneracy around _{}_{\tau}  1.6.

High energy events help distinguish signal from background in constraining new physics.

Constraints on decoherence parameter  are obtained from 1 to 20 GeV energy range.

Abstract

NuMI Off-axis $\nu_e$ Appearance (NOvA) experiment is an ongoing long baseline neutrino oscillation experiment. The primary channels of interest are the $\nu_e$, $\bar{\nu}_e$ appearance, $\nu_\mu$, $\bar{\nu}_\mu$ disappearance channels analyzed in the energy window $1< E_\nu < 4$ GeV. However, NOvA far detector sees non-trivial high energy $\nu_e$, $\bar{\nu}_e$ events in the energy range $4 < E_\nu < 20$ GeV. These high energy events provide us with an opportunity to investigate the subleading new physics scenarios. In this context, we study the sensitivity of the NOvA experiment to constrain the non-standard interaction (NSI) parameters and environmental decoherence. We observe that by including high energy events (signal + background) the degeneracy around $\epsilon_{e\tau} \sim 1.6$ can be removed throughout the $\delta_{CP}$ and $\delta_{e\tau}$ range. Further, we examine the role of signal versus beam background events in removing this degeneracy. In addition, we constrain the decoherence parameter $\Gamma$ considering events from $1<E_\nu<20$ GeV. Later, assuming the presence of decoherence in nature we obtain the allowed regions in $\theta_{23}$ and $\delta_{CP}$ plane.